What is VistA Really - Revision history

NeilArmstrong: Added glossary link to Clinical Users~

2012-02-28T08:00:37Z

Added glossary link to Clinical Users~

← Older revision		Revision as of 08:00, 28 February 2012
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	The [http://www.hardhats.org/history/hardhats.html history of VistA available from Hardhats.org] indicates that VistA development began in the late 1970's. VA documents, such as the [http://www.va.gov/vista_monograph/ VistA Monograph], date the start of VistA to the mid 1980's. Why the discrepancy? In short, the version at Hardhats is the real version. It documents how VistA moved from an underground movement to a celebrated system.		The [http://www.hardhats.org/history/hardhats.html history of VistA available from Hardhats.org] indicates that VistA development began in the late 1970's. VA documents, such as the [http://www.va.gov/vista_monograph/ VistA Monograph], date the start of VistA to the mid 1980's. Why the discrepancy? In short, the version at Hardhats is the real version. It documents how VistA moved from an underground movement to a celebrated system.

	VistA (and the vision that led to it) was a programmer-led counter-culture within the VA. Programmers and administrators often risked their jobs (and some lost them) in order to develop a system that would satisfy clinical needs at local hospitals. Each programmer was primarily interested in the needs of the clinical users who worked at the same local VA hospital that the programmer worked at. Nevertheless, they desired that the software they created would be able to be used throughout the VA system.		VistA (and the vision that led to it) was a programmer-led counter-culture within the VA. Programmers and administrators often risked their jobs (and some lost them) in order to develop a system that would satisfy clinical needs at local hospitals. Each programmer was primarily interested in the needs of the [[clinical users~\|Clinical Users]] who worked at the same local VA hospital that the programmer worked at. Nevertheless, they desired that the software they created would be able to be used throughout the VA system.

	The software platform that eventually resulted was unique because it represented a combination of modules developed by a distributed team. The method of the creation of VistA was, therefore, a precursor to the distributed "open source" development style now popular today.		The software platform that eventually resulted was unique because it represented a combination of modules developed by a distributed team. The method of the creation of VistA was, therefore, a precursor to the distributed "open source" development style now popular today.

NeilArmstrong: Added glossary link to Application~

2012-02-22T14:14:32Z

Added glossary link to Application~

← Older revision		Revision as of 14:14, 22 February 2012
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	== The terminal interface versus the CPRS GUI ==		== The terminal interface versus the CPRS GUI ==

	Many people who have used VistA think that CPRS '''is''' VistA. However, CPRS is only a GUI frontend for some of the functions the VistA server/database can provide. Many of the other functions are accessed by "command-line" or "roll and scroll" terminal ~~applications~~.		Many people who have used VistA think that CPRS '''is''' VistA. However, CPRS is only a GUI frontend for some of the functions the VistA server/database can provide. Many of the other functions are accessed by "command-line" or "roll and scroll" terminal [[application~\|Application]]s.

	Because clinicians often need graphical displays (for charts, for example) that are not possible in terminal ~~applications~~, CPRS was created to perform most of the common clinical functions in a GUI environment. CPRS is written in Borland's Delphi (Pascal). It uses VistA-RPC calls to connect to the VistA server/database. (For more clarification, read about the [[How_does_VistA_work\|basic VistA architecture]].)		Because clinicians often need graphical displays (for charts, for example) that are not possible in terminal [[application~\|Application]]s, CPRS was created to perform most of the common clinical functions in a GUI environment. CPRS is written in Borland's Delphi (Pascal). It uses VistA-RPC calls to connect to the VistA server/database. (For more clarification, read about the [[How_does_VistA_work\|basic VistA architecture]].)

	However, VistA was initially designed before monitors were capable of complex graphics displays. Older monitors that only could display text were called "terminals".		However, VistA was initially designed before monitors were capable of complex graphics displays. Older monitors that only could display text were called "terminals".

	Therefore, most of the functionality of the VistA server/ MUMPS database was initially accessed through terminal ("command-line" or "roll-and-scroll") interfaces. In fact, much of VistA is still only available through such terminal ~~applications~~ (currently). (Many consumer-grade desktop computers use [http://en.wikipedia.org/wiki/Terminal_emulator Terminal Emulators], allowing them to interface with ~~applications~~ in the same way a terminal would.)		Therefore, most of the functionality of the VistA server/ MUMPS database was initially accessed through terminal ("command-line" or "roll-and-scroll") interfaces. In fact, much of VistA is still only available through such terminal [[application~\|Application]]s (currently). (Many consumer-grade desktop computers use [http://en.wikipedia.org/wiki/Terminal_emulator Terminal Emulators], allowing them to interface with [[application~\|Application]]s in the same way a terminal would.)

	Many people unjustly dismiss terminal ~~applications~~. While GUIs may make learning to use a software programs easier, terminal ~~applications~~ are generally faster to use on a routine basis. Once the initial learning curve is overcome, terminals offer faster data entry and better response times than most GUI ~~applications~~. When given the choice, experienced users often prefer the terminal (and lose productivity when forced to use GUIs). Text-based (i.e. terminal-based) ~~applications~~ are highly predictable about where they display information, whereas GUIs can often change the location of information on the screen and require time to manipulate the mouse around the screen to figure out where to enter data.		Many people unjustly dismiss terminal [[application~\|Application]]s. While GUIs may make learning to use a software programs easier, terminal [[application~\|Application]]s are generally faster to use on a routine basis. Once the initial learning curve is overcome, terminals offer faster data entry and better response times than most GUI [[application~\|Application]]s. When given the choice, experienced users often prefer the terminal (and lose productivity when forced to use GUIs). Text-based (i.e. terminal-based) [[application~\|Application]]s are highly predictable about where they display information, whereas GUIs can often change the location of information on the screen and require time to manipulate the mouse around the screen to figure out where to enter data.

	A person who only rarely uses a program must usually figure out how to use it again every time. For such a person a GUI is generally a desirable interface, with pull-down menus that can eventually tell them which option to select.		A person who only rarely uses a program must usually figure out how to use it again every time. For such a person a GUI is generally a desirable interface, with pull-down menus that can eventually tell them which option to select.
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	CPRS provides a very well-thought-out approach to its interfacing with VistA's capabilities. It is relatively easy to use, given its complexity and depth. A quick look at the [http://scholar.google.com/scholar?hl=en&lr=&q=CPRS+VistA&btnG=Search Google Scholar search for "VistA" and "CPRS"] reveals that CPRS is one of the most studied EHR interfaces available.		CPRS provides a very well-thought-out approach to its interfacing with VistA's capabilities. It is relatively easy to use, given its complexity and depth. A quick look at the [http://scholar.google.com/scholar?hl=en&lr=&q=CPRS+VistA&btnG=Search Google Scholar search for "VistA" and "CPRS"] reveals that CPRS is one of the most studied EHR interfaces available.

	CPRS is also very customizable. In the VA, a "[[Clinical Application Coordinator]]" (CAC) is responsible for the care and maintenance of local installations of the CPRS client on clinicians' computers. A competent CAC is capable of tuning CPRS in numerous ways to the preferences of individual departments or even individual clinicians. The CPRS menu can even link to other programs, so that clinical programs that are actually separate ~~applications~~ can appear to be a part of CPRS.		CPRS is also very customizable. In the VA, a "[[Clinical Application Coordinator]]" (CAC) is responsible for the care and maintenance of local installations of the CPRS client on clinicians' computers. A competent CAC is capable of tuning CPRS in numerous ways to the preferences of individual departments or even individual clinicians. The CPRS menu can even link to other programs, so that clinical programs that are actually separate [[Application~\|application]]s can appear to be a part of CPRS.

	CPRS is often criticized for being "long in the tooth" (too old). It is written in Delphi (which is no longer as popular a programming language as it was in the mid 1980s). Like the rest of VistA, CPRS was written at a time when computers were much slower. As a result CPRS is quite lightweight and fast. While the IT community might seek a [[Compelling CPRS Replacement\|compelling CPRS replacement]], CPRS itself is one of the only solutions that can run (and continues to run) on computers that are too old to run any other commonly deployed proprietary EHR systems.		CPRS is often criticized for being "long in the tooth" (too old). It is written in Delphi (which is no longer as popular a programming language as it was in the mid 1980s). Like the rest of VistA, CPRS was written at a time when computers were much slower. As a result CPRS is quite lightweight and fast. While the IT community might seek a [[Compelling CPRS Replacement\|compelling CPRS replacement]], CPRS itself is one of the only solutions that can run (and continues to run) on computers that are too old to run any other commonly deployed proprietary EHR systems.

Ftrotter: cleanups and OSEHRA links

2011-09-09T01:52:13Z

cleanups and OSEHRA links

DavidWhitten at 18:48, 6 August 2011

2011-08-06T18:48:43Z

← Older revision		Revision as of 18:48, 6 August 2011
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	Despite the way in which VistA was developed, there is a common misconception that VistA is "open source" software. Technically, VistA is in the [http://en.wikipedia.org/wiki/Public_domain public domain]. As a result VistA can legally be the basis of both proprietary software and "free and open source" software. [http://www.linuxmednews.com/974769856/index_html FOIA VistA does meet the strict definition of "free software"].		Despite the way in which VistA was developed, there is a common misconception that VistA is "open source" software. Technically, VistA is in the [http://en.wikipedia.org/wiki/Public_domain public domain]. As a result VistA can legally be the basis of both proprietary software and "free and open source" software. [http://www.linuxmednews.com/974769856/index_html FOIA VistA does meet the strict definition of "free software"].

	The fact that VistA can be proprietary software AND free software creates an ongoing tension between different portions of the VistA community. For instance WorldVistA has a policy of releasing software under the [http://en.wikipedia.org/w/index.php?title=GPL General Public License (GPL)]. The GPL is a "keep-it-free" license that prevents someone from controlling the software and making it unavailable to others. However, some VistA vendors favor licenses (such as the Apache License), that allow for Open Source development to be used in proprietary products.		The fact that VistA can be proprietary software AND free software creates an ongoing tension between different portions of the VistA community. For instance WorldVistA has a policy of releasing software under the [http://en.wikipedia.org/w/index.php?title=GPL General Public License (GPL)]. The GPL is a "keep-it-free" license that prevents someone from controlling the software and making it unavailable to others. However, some VistA vendors favor licenses (such as the Apache License), that allow for Open Source development to be used in proprietary products. Alternately, some VistA vendors favor licenses (such as the LGPL), that allow for add-on modules to be used in proprietary packages.

	== What do you mean by... ==		== What do you mean by... ==

Ftrotter: /* A Cloudy History */ it is desputed, not cloudy

2011-08-02T22:41:25Z

A Cloudy History: it is desputed, not cloudy

← Older revision		Revision as of 22:41, 2 August 2011
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	VistA is an '''Electronic Health Record''' programmed by federal (US) employees working for the Department of Veterans Affairs (previously the Veterans Administration) for several decades. Because it was developed by federal employees, it is available under a Freedom of Information Act (FOIA) request. (The version of VistA available directly from the US Government is usually referred to as FOIA VistA.)		VistA is an '''Electronic Health Record''' programmed by federal (US) employees working for the Department of Veterans Affairs (previously the Veterans Administration) for several decades. Because it was developed by federal employees, it is available under a Freedom of Information Act (FOIA) request. (The version of VistA available directly from the US Government is usually referred to as FOIA VistA.)

	== A ~~Cloudy~~ History ==		== A Disputed History ==
	The [http://www.hardhats.org/history/hardhats.html history of VistA available from Hardhats.org] indicates that VistA development began in the late 1970's. VA documents, such as the [http://www.va.gov/vista_monograph/ VistA Monograph], date the start of VistA to the mid 1980's. Why the discrepancy? In short, the version at Hardhats is the real version. It documents how VistA moved from an underground movement to a celebrated system.		The [http://www.hardhats.org/history/hardhats.html history of VistA available from Hardhats.org] indicates that VistA development began in the late 1970's. VA documents, such as the [http://www.va.gov/vista_monograph/ VistA Monograph], date the start of VistA to the mid 1980's. Why the discrepancy? In short, the version at Hardhats is the real version. It documents how VistA moved from an underground movement to a celebrated system.

Ftrotter: /* Your programming language is named after a disease? */ they -are- a dying breed.

2011-08-02T22:36:52Z

Your programming language is named after a disease?: they -are- a dying breed.

← Older revision		Revision as of 22:36, 2 August 2011
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	Some business analysts have also expressed apprehension regarding the prevalence and longevity of MUMPS, and some misconceptions have been propagated as a result.		Some business analysts have also expressed apprehension regarding the prevalence and longevity of MUMPS, and some misconceptions have been propagated as a result.

	* "~~Compared~~ to ~~the number of programmers in mainstream programming languages, there are relatively few qualified~~ MUMPS ~~programmers~~." While there are more MUMPS programmers than there are for SNOBOL (or other programming languages of the same generation), there clearly are less than for other more ~~pervasive databases~~. ~~Nevertheless,~~ MUMPS ~~is used widely in health care and banking, so while~~ programmers ~~are not on every street corner~~, they are not a ~~dying breed~~.		* "We will not be able to find a MUMPS programmer." While there are more MUMPS programmers than there are for SNOBOL (or other programming languages of the same generation), there clearly are less than for other more common programming languages. You can find MUMPS programmers, but they are retiring and not being replaced by new programmers who have an interest in learning the language. So this is certainly a problem, but it is not absolute.

	* "It takes a competent computer scientist much longer to learn MUMPS than other languages." MUMPS maintains backward compatibility to ideas that recent computer science graduates don't see much (except in assembly language programming), such as the GOTO command or line tags.		* "It takes a competent computer scientist much longer to learn MUMPS than other languages." MUMPS maintains backward compatibility to ideas that recent computer science graduates don't see much (except in assembly language programming), such as the GOTO command or line tags. It does take programmers longer to pick up, but it is possible to do.

	* "Because they are rare, MUMPS programmers are often expensive." Just like diamonds, platinum, and titanium.		* "Because they are rare, MUMPS programmers are often expensive." Just like diamonds, platinum, and titanium.

Ftrotter: /* Licensing of FOIA VistA */ it has nothing to do with modules

2011-08-02T22:31:17Z

Licensing of FOIA VistA: it has nothing to do with modules

← Older revision		Revision as of 22:31, 2 August 2011
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	Despite the way in which VistA was developed, there is a common misconception that VistA is "open source" software. Technically, VistA is in the [http://en.wikipedia.org/wiki/Public_domain public domain]. As a result VistA can legally be the basis of both proprietary software and "free and open source" software. [http://www.linuxmednews.com/974769856/index_html FOIA VistA does meet the strict definition of "free software"].		Despite the way in which VistA was developed, there is a common misconception that VistA is "open source" software. Technically, VistA is in the [http://en.wikipedia.org/wiki/Public_domain public domain]. As a result VistA can legally be the basis of both proprietary software and "free and open source" software. [http://www.linuxmednews.com/974769856/index_html FOIA VistA does meet the strict definition of "free software"].

	The fact that VistA can be proprietary software AND free software creates an ongoing tension between different portions of the VistA community. For instance WorldVistA has a policy of releasing software under the [http://en.wikipedia.org/w/index.php?title=GPL General Public License (GPL)]. The GPL is a "keep-it-free" license that prevents someone from controlling the software and making it unavailable to others. However, some VistA vendors favor licenses (such as the ~~LGPL~~), that allow for ~~add-on modules~~ to be used in proprietary ~~packages~~.		The fact that VistA can be proprietary software AND free software creates an ongoing tension between different portions of the VistA community. For instance WorldVistA has a policy of releasing software under the [http://en.wikipedia.org/w/index.php?title=GPL General Public License (GPL)]. The GPL is a "keep-it-free" license that prevents someone from controlling the software and making it unavailable to others. However, some VistA vendors favor licenses (such as the Apache License), that allow for Open Source development to be used in proprietary products.

	== What do you mean by... ==		== What do you mean by... ==

Perspectoff: /* Other Resources */

2010-02-01T05:24:51Z

Other Resources

← Older revision		Revision as of 05:24, 1 February 2010
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	== Other Resources ==		== Other Resources ==
	* This page was originally written by Fred Trotter. Please send comments and suggestion to him directly at [http://www.fredtrotter.com his blog].		* This page was originally written by Fred Trotter. Please send comments and suggestion to him directly at [http://www.fredtrotter.com his blog].
			*The best description of the style of distributed software development is in a paper called [http://catb.org/~esr/writings/cathedral-bazaar/cathedral-bazaar/ "The Cathedral and the Bazaar"] by Eric Raymond.

Perspectoff: /* A Cloudy History */

2010-02-01T05:23:56Z

A Cloudy History

← Older revision		Revision as of 05:23, 1 February 2010
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	VistA (and the vision that led to it) was a programmer-led counter-culture within the VA. Programmers and administrators often risked their jobs (and some lost them) in order to develop a system that would satisfy clinical needs at local hospitals. Each programmer was primarily interested in the needs of the clinical users who worked at the same local VA hospital that the programmer worked at. Nevertheless, they desired that the software they created would be able to be used throughout the VA system.		VistA (and the vision that led to it) was a programmer-led counter-culture within the VA. Programmers and administrators often risked their jobs (and some lost them) in order to develop a system that would satisfy clinical needs at local hospitals. Each programmer was primarily interested in the needs of the clinical users who worked at the same local VA hospital that the programmer worked at. Nevertheless, they desired that the software they created would be able to be used throughout the VA system.

	The software platform that eventually resulted was unique because it represented a combination of modules developed by a distributed team. The method of the creation of VistA was, therefore, a precursor to the distributed "open source" development style now popular today. ~~[The best description of this style of distributed development is in a paper called [http://catb.org/~esr/writings/cathedral-bazaar/cathedral-bazaar/ "The Cathedral and the Bazaar"] by Eric Raymond.]~~		The software platform that eventually resulted was unique because it represented a combination of modules developed by a distributed team. The method of the creation of VistA was, therefore, a precursor to the distributed "open source" development style now popular today.

	Even the original name reflected the nature of its development: Decentralized Hospital Computer Program (DHCP). (The name "VistA" was not chosen until much later.)		Even the original name reflected the nature of its development: Decentralized Hospital Computer Program (DHCP). (The name "VistA" was not chosen until much later.)

Perspectoff: /* Your programming language is named after a disease? */

2010-02-01T05:22:24Z

Your programming language is named after a disease?

← Older revision		Revision as of 05:22, 1 February 2010
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	* MUMPS is not a C-based syntax, as most modern programming languages are. This means that MUMPS code looks strange to outsiders.		* MUMPS is not a C-based syntax, as most modern programming languages are. This means that MUMPS code looks strange to outsiders.
	* MUMPS is not white space invariant. This means that you must pay attention to where you put spaces. Many modern program languages allow you to freely put in spaces at any point (following FORTRAN rules originally) With MUMPS you must be careful where you indent using spaces. Putting multiple spaces in some places is not allowed at all~~, which~~ will really bother you if you like ~~python~~ (which forces indentation as part of the syntax instead of using periods as MUMPS does)		* MUMPS is not white space invariant. This means that you must pay attention to where you put spaces. Many modern program languages allow you to freely put in spaces at any point (following FORTRAN rules originally). With MUMPS you must be careful where you indent using spaces. Putting multiple spaces in some places is not allowed at all. (This will really bother you if you like Python (which forces indentation as part of the syntax instead of using periods as MUMPS does)).
	* MUMPS is its own database, but its database is not SQL. It's a [http://en.wikipedia.org/wiki/Hierarchical_model Hierarchical Database] that is ideally suited to healthcare		* MUMPS is its own database, but its database is not SQL. It's a [http://en.wikipedia.org/wiki/Hierarchical_model Hierarchical Database] that is ideally suited to healthcare.
	* ~~Globals (~~variables~~) means~~ something in the permanent database, ~~ie:~~ global across all processes in the system, not the typical programming meaning of global across all the subparts of a single program (variables that are shared within all parts of a single program are called locals in MUMPS).		* Global variables mean something in the permanent database, i.e., global across all processes in the system, not the typical programming meaning of global across all the subparts of a single program (variables that are shared within all parts of a single program are called locals in MUMPS).
	* MUMPS often behaves like an operating system. Due to space limitations, some original implementations of MUMPS actually were the operating systems on the machine~~, and this~~ legacy still influences the behavior of MUMPS.		* MUMPS often behaves like an operating system. Due to space limitations, some original implementations of MUMPS actually were the operating systems on the machine. This legacy still influences the behavior of MUMPS.

	Some business analysts ~~express~~ apprehension regarding the prevalence and longevity of MUMPS, and some misconceptions have been propagated as a result.		Some business analysts have also expressed apprehension regarding the prevalence and longevity of MUMPS, and some misconceptions have been propagated as a result.

	* "Compared to the number of programmers in mainstream programming languages, there are relatively few qualified MUMPS programmers." While there are more MUMPS programmers than there are for SNOBOL (or other programming languages of the same generation), there clearly are less than for other more pervasive databases. Nevertheless, MUMPS is used widely in health care and banking, so while programmers are not on every street corner, they are not a dying breed.		* "Compared to the number of programmers in mainstream programming languages, there are relatively few qualified MUMPS programmers." While there are more MUMPS programmers than there are for SNOBOL (or other programming languages of the same generation), there clearly are less than for other more pervasive databases. Nevertheless, MUMPS is used widely in health care and banking, so while programmers are not on every street corner, they are not a dying breed.

← Older revision		Revision as of 01:52, 9 September 2011
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	VistA is an '''Electronic Health Record''' programmed by federal (US) employees working for the Department of Veterans Affairs (previously the Veterans Administration) for several decades. Because it was ~~developed~~ by federal employees, it is available under a Freedom of Information Act (FOIA) request. (The version of VistA available directly from the US Government is usually referred to as FOIA VistA.)		VistA is an '''Electronic Health Record''' programmed by federal (US) employees working for the Department of Veterans Affairs (previously the Veterans Administration) for several decades. Because it was created by federal employees, it is available to the public under a Freedom of Information Act (FOIA) request. (The version of VistA available directly from the US Government is usually referred to as FOIA VistA.)

	== A Disputed History ==		== A Disputed History ==
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	The VA bureaucracy is primarily concerned (as it should be) with the care of veterans. As one can imagine, this is a highly political issue with tremendous pressure from Washington. Enlightenment with regard to the development of VistA is largely independent of bureaucratic ability. When the VA is lead by VistA-enlightened leadership, VistA tends to thrive and move forward. When the VA is led by those ignorant of VistA and software generally, VistA tends to stagnate.		The VA bureaucracy is primarily concerned (as it should be) with the care of veterans. As one can imagine, this is a highly political issue with tremendous pressure from Washington. Enlightenment with regard to the development of VistA is largely independent of bureaucratic ability. When the VA is lead by VistA-enlightened leadership, VistA tends to thrive and move forward. When the VA is led by those ignorant of VistA and software generally, VistA tends to stagnate.

	The tension between those who actually make VistA work well (the VistA programmers, ADPACs, and CACs) and the bureaucracy that is in charge of the VA resources still exists. In many ways the purpose of WorldVistA is to ease this tension. WorldVistA is intended to be a neutral meeting place that can include VA programmers and VA bureaucrats that is external to the VA.		The tension between those who actually make VistA work well (the VistA programmers, ADPACs, and CACs) and the bureaucracy that is in charge of the VA resources still exists. In many ways the purpose of WorldVistA is to ease this tension. WorldVistA was intended to be a neutral meeting place that can include VA programmers and VA bureaucrats that is external to the VA.

	~~The common theme in~~ the ~~WorldVistA community is~~ the ~~interest in~~ VistA and ~~making~~ the ~~software better~~.		Recently the VA has created a new non-profit called [http://www.osehra.org/ OSEHRA] to manage the development of VistA and to coordinate between VistA development inside and outside the VA.

	== Licensing of FOIA VistA ==		== Licensing of FOIA VistA ==

	Despite the way in which VistA was developed, there is a common misconception that VistA is "open source" software. Technically, VistA is in the [http://en.wikipedia.org/wiki/Public_domain public domain]. As a result VistA can legally be the basis of both proprietary software and "free and open source" software. [http://www.linuxmednews.com/974769856/index_html FOIA VistA does meet the strict definition of "free software"].		Despite the way in which VistA was developed, there is a common misconception that VistA is "open source" software. Technically, VistA is in the [http://en.wikipedia.org/wiki/Public_domain public domain]. As a result FOIA VistA can legally be the basis of both proprietary software and "free and open source" software. [http://www.linuxmednews.com/974769856/index_html FOIA VistA does meet the strict definition of "free software"]. VistA can also be licensed under a combination of proprietary and Open Source license, which is often called a hybrid approach.

	The fact that VistA can be proprietary software AND free software creates an ongoing tension between different portions of the VistA community. For instance WorldVistA has a policy of releasing software under the [http://en.wikipedia.org/w/index.php?title=GPL General Public License (GPL)]. The GPL is a "keep-it-free" license that prevents ~~someone~~ from controlling the software and making it unavailable to others. However, some VistA vendors favor licenses (such as the Apache License), that allow for Open Source development to be used in proprietary products. ~~Alternately, some~~ VistA ~~vendors~~ favor ~~licenses (such as~~ the ~~LGPL)~~, ~~that allow~~ for add-~~on modules~~ to ~~be used in proprietary packages~~.		The fact that VistA can be proprietary software AND free software creates an ongoing tension between different portions of the VistA community. For instance, WorldVistA has a policy of releasing software under the [http://en.wikipedia.org/w/index.php?title=GPL General Public License (GPL)]. The GPL is a "keep-it-free" license that prevents one from controlling the software source code and making it unavailable to others. However, some VistA vendors favor licenses (such as the Apache License), that allow for Open Source development to be used in proprietary products.

			Some in the VistA community favor the open core concept, where a proprietary-friendly Open Source license is chosen for the core software package. This allows both Open Source and proprietary modules as add-ons to the core. Currently this is the licensing approach taken by [http://www.osehra.org/ OSEHRA]

	== What do you mean by... ==		== What do you mean by... ==
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	A barrier to understanding VistA is often one of overlapping vocabularies. Paradoxically, people who are technically savvy may have a more difficult time with the vocabulary than those with less IT experience. This is because VistA was developed in parallel with many technologies that today we take for granted. Names for technologies in the time-honored VistA lexicon may overlap with names of more recent technologies (causing a degree of confusion for new VistA developers).		A barrier to understanding VistA is often one of overlapping vocabularies. Paradoxically, people who are technically savvy may have a more difficult time with the vocabulary than those with less IT experience. This is because VistA was developed in parallel with many technologies that today we take for granted. Names for technologies in the time-honored VistA lexicon may overlap with names of more recent technologies (causing a degree of confusion for new VistA developers).

	"RPC" is a good example. When people outside the VistA Community refer to [http://en.wikipedia.org/wiki/Remote_procedure_call RPC], they usually are referring to a somewhat ubiquitous *nix messaging system. VistA developers and users, in contrast, ~~may~~ speak of the the [[VistA RPC]], a method of connecting CPRS clients to a VistA server. While the more recent RPC is based on the same basic idea as the [[VistA RPC]], on closer inspection they do ~~not~~ bear ~~much~~ resemblance to each other.		"RPC" is a good example. When people outside the VistA Community refer to [http://en.wikipedia.org/wiki/Remote_procedure_call RPC], they usually are referring to a somewhat ubiquitous *nix messaging system. VistA developers and users, in contrast, speak of the the [[VistA RPC]], a method of connecting CPRS clients to a VistA server. While the more recent XML-RPC network protocol is based on the same basic idea as the [[VistA RPC]], on closer inspection they do bear little resemblance to each other.

	Here are some other [[Confusing Terms]].		Here are some other [[Confusing Terms]].
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	* MUMPS is not a C-based syntax, as most modern programming languages are. This means that MUMPS code looks strange to outsiders.		* MUMPS is not a C-based syntax, as most modern programming languages are. This means that MUMPS code looks strange to outsiders.
	* MUMPS is not white space invariant. This means that you must pay attention to where you put spaces. Many modern program languages allow you to freely put in spaces at any point ~~(following FORTRAN rules originally)~~. With MUMPS you must be careful where you indent using spaces. Putting multiple spaces in some places is not allowed at all. (This will really bother ~~you if you~~ like Python (which forces indentation as part of the syntax instead of using periods as MUMPS does)).		* MUMPS is not white space invariant. This means that you must pay attention to where you put spaces. Many modern program languages allow you to freely put in spaces at any point. With MUMPS you must be careful where you indent using spaces. Putting multiple spaces in some places is not allowed at all. (This will really bother those who like Python which forces indentation as part of the syntax instead of using periods as MUMPS does).
	* MUMPS is its own database, but its database is not SQL. It's a [http://en.wikipedia.org/wiki/Hierarchical_model Hierarchical Database] that is ideally suited to healthcare.		* MUMPS is its own database, but its database is not SQL. It's a [http://en.wikipedia.org/wiki/Hierarchical_model Hierarchical Database] that is ideally suited to healthcare. MUMPS can be thought of as an old-school NoSQL database.
	* Global variables mean something in the permanent database, i.e., global across all processes in the system, not the typical programming meaning of global across all the subparts of a single program (variables that are shared within all parts of a single program are called locals in MUMPS).		* Global variables mean something in the permanent database, i.e., global across all processes in the system, not the typical programming meaning of global across all the subparts of a single program (variables that are shared within all parts of a single program are called locals in MUMPS).
	* MUMPS often behaves like an operating system. Due to space limitations, some original implementations of MUMPS actually were the operating systems on the machine. This legacy still influences the behavior of MUMPS.		* MUMPS often behaves like an operating system. Due to space limitations, some original implementations of MUMPS actually were the operating systems on the machine. This legacy still influences the behavior of MUMPS.
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	Some business analysts have also expressed apprehension regarding the prevalence and longevity of MUMPS, and some misconceptions have been propagated as a result.		Some business analysts have also expressed apprehension regarding the prevalence and longevity of MUMPS, and some misconceptions have been propagated as a result.

	* "We will not be able to find a MUMPS programmer." While there are more MUMPS programmers than there are for SNOBOL (or other programming languages of the same generation), there clearly are less than for other more common programming languages. You can find MUMPS programmers, but they are retiring and not being replaced by new programmers who have an interest in learning the language. So this is certainly a problem, but it is not absolute.		* "We will not be able to find a MUMPS programmer." While there are more MUMPS programmers than there are for SNOBOL (or other programming languages of the same generation), there clearly are less than for other more common programming languages. You can find MUMPS programmers, but they are retiring and not being replaced by new programmers who have an interest in learning the language. So this is certainly a problem, but it is not an absolute.

	* "It takes a competent computer scientist much longer to learn MUMPS than other languages." MUMPS maintains backward compatibility to ideas that recent computer science graduates don't see much (except in assembly language programming), such as the GOTO command or line tags. It does take programmers longer to pick up, but it is possible ~~to do~~.		* "It takes a competent computer scientist much longer to learn MUMPS than other languages." MUMPS maintains backward compatibility to ideas that recent computer science graduates don't see much (except in assembly language programming), such as the GOTO command or line tags. It does take programmers longer to pick up, but it is possible.

	* "Because they are rare, MUMPS programmers are often expensive." Just like diamonds, platinum, and titanium.		* "Because they are rare, MUMPS programmers are often expensive." Just like diamonds, platinum, and titanium.
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	CPRS is also very customizable. In the VA, a "[[Clinical Application Coordinator]]" (CAC) is responsible for the care and maintenance of local installations of the CPRS client on clinicians' computers. A competent CAC is capable of tuning CPRS in numerous ways to the preferences of individual departments or even individual clinicians. The CPRS menu can even link to other programs, so that clinical programs that are actually separate applications can appear to be a part of CPRS.		CPRS is also very customizable. In the VA, a "[[Clinical Application Coordinator]]" (CAC) is responsible for the care and maintenance of local installations of the CPRS client on clinicians' computers. A competent CAC is capable of tuning CPRS in numerous ways to the preferences of individual departments or even individual clinicians. The CPRS menu can even link to other programs, so that clinical programs that are actually separate applications can appear to be a part of CPRS.

	CPRS is often criticized ~~by recent programmers~~ for being "long in the tooth" (too old). It is written in Delphi (which is no longer as popular a programming language as it was in the mid 1980s). Like the rest of VistA, CPRS was written at a time when computers were much slower. As a result CPRS is quite lightweight and fast. While the IT community might seek a [[Compelling CPRS Replacement\|compelling CPRS replacement]], CPRS itself is one of the only solutions that can run (and continues to run) on computers that are too old to run any other commonly deployed proprietary EHR systems.		CPRS is often criticized for being "long in the tooth" (too old). It is written in Delphi (which is no longer as popular a programming language as it was in the mid 1980s). Like the rest of VistA, CPRS was written at a time when computers were much slower. As a result CPRS is quite lightweight and fast. While the IT community might seek a [[Compelling CPRS Replacement\|compelling CPRS replacement]], CPRS itself is one of the only solutions that can run (and continues to run) on computers that are too old to run any other commonly deployed proprietary EHR systems.

	== Other Resources ==		== Other Resources ==
	* This page was originally written by Fred Trotter. Please send comments and suggestion to him directly at [http://www.fredtrotter.com his blog].		* This page was originally written by Fred Trotter. Please send comments and suggestion to him directly at [http://www.fredtrotter.com his blog].
	*The best description of the style of distributed software development is in a paper called [http://catb.org/~esr/writings/cathedral-bazaar/cathedral-bazaar/ "The Cathedral and the Bazaar"] by Eric Raymond.		*The best description of the style of distributed software development is in a paper called [http://catb.org/~esr/writings/cathedral-bazaar/cathedral-bazaar/ "The Cathedral and the Bazaar"] by Eric Raymond.