Open Source Software Licenses

• Author: David W. Tollen
• Pages: 247-253

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APPENDIX 2

Open Source Software Licenses

An open source license grants the customer access to the software’s

source code. It also permits modification of the software and redis-

tribution of both the original and the new, modified version. At least,

that’s a thumbnail explanation of a complex concept. This appendix

explains open source licenses. You’ll understand this appendix better

if you first read Chapter I.C (“Software Licenses in General”).6

This appendix refers to the parties in an open source license

as the “licensor” and the “recipient.” That’s because “vendor” and

“customer” don’t fit well, since often both parties qualify as software

developers and distributors.

“Open source” is often confused with “free,” but open source

software isn’t necessarily free. Licensors can charge for software and

still be considered open source providers, so long as they don’t charge

any additional fee or royalty for source code or for the rights to mod-

ify and redistribute. But because each recipient can redistribute the

software—at any price or no price—market forces usually keep licen-

sors from charging a lot. If the price is high, recipients can just get

the software from someone else: from another recipient. As a result,

much open source software actually is free or very inexpensive. Most

of the licensors don’t care about making money directly from their

software. They generate revenues from related professional services,

6. The open source community doesn’t consider its licenses “contracts.” A hazy line

separates licenses and contracts that include licenses. In simplified terms, a license grants

rights without any corresponding promises from the recipient, while a contract involves

promises from both sides (or at least promises in exchange for actions).

For a more complete definition of “open source,” see The Open Source Definition

provided by the Open Source Initiative: http://www.opensource.org/docs/osd.