What Is Open-Source Software?

Open source software is not just “free” software: the real question is what the licence allows, what the user still has to pay for, and what legal and practical limits remain.

US federal law (Public Law 115-232) defines open source software as software for which the human-readable source code is available for use, study, re-use, modification, enhancement, and re-distribution by the users of such software. The Open Source Initiative’s (OSI) Open Source Definition is the widely adopted formal standard for open source, and a licence must meet all ten of its criteria before qualifying.

Open Source Means Licence Rights

The Open Source Initiative says open source software can be used freely, changed, and shared in modified or unmodified form by anyone - as long as the licence permits it. The OSI states that access to source code alone is not enough to make software open source; the licence must also allow modification and redistribution under the same terms and all uses, including commercial use.

Most of all: open source is not the same thing as “free of charge” - the Open Source Definition allows software to be sold and only forbids royalties for redistribution; the US Centers for Medicare & Medicaid Services describes open source software as freely licensed, not as costless to support, adapt, or distribute in every case. Open source software is often distributed under OSI-approved licences that allow free redistribution, provide the source code, allow modifications and derived works, and are technology-neutral.

What the Licence Allows

A licence is the legal mechanism that freely distributes open source software. The OSI's Open Source Definition defines the nuts and bolts of what that means: the licence has to satisfy ten conditions. The simplified core of this is that the software must give users the right to change and reuse the software.

What this allows in practice is the freedom to run the program for any purpose, to study how the software works and change it so it does what the user wishes, to redistribute copies; and to distribute modified versions of the software.

What Still Costs Money

Using Open Source Software at work very often comes with maintenance and support costs. Even if the licence does not conflict with the intended classroom or workplace use, it does not mean there are no additional costs to budget. As a general rule, the user may need to acquire any adaptations for the sector or any support they require.

What to Check Before Using it at Work

It is important to check these rights, especially when the software is being used in a business, government or charity context.

The license, therefore, cannot discriminate against any use or implementation of software, nor restrict its deployment into specific situations or applications, and nor may it give the right to deny or exclude anyone from access.

Use of the software in commercial applications is also permitted. This is because the Open Source Initiative's definition framework allows for commercial use.

What Cannot Be Claimed Without Proof

Then again, the fact that OSS is open source doesn’t make it immune from costs such as adaptations, updates and distribution. And there is no assurance that OSS offers perfect protection or flexibility for every use.

Open source software is not automatically less risky than closed-source software. It comes with no universal assurance of improved security. No security systems are without their own vulnerabilities and, while open source may be thought to allow easier handling of bugs, transparency alone does not imply an obligation. In fact, the OSI does not promise expressively that OSS is devoid of vulnerabilities.

Classroom and business application of OSS still requires careful reading

Overall therefore, people aiming to own or re-distribute a copy of OSS, have to remember that freedom of ‘contract’, even an open one, takes careful reading.

The OSI describes itself as “the global nonprofit building the future powered by open collaboration, transparency and innovation.” That mission statement is no guarantee that open source software will outweigh the risks and costs of implementing and supporting software.

That's the real measure of how OSS may be used, studied, changed and shared.