5.1.6. Licensing Models
- GPL and LGPL
- GPL guarantees the following freedoms (as in free speech, not free beer)
- You can run the program as you wish for any purpose
- You can study the source code and change it to do what you want
- You can make copies and distribute them
- You can distribute modified versions
- Derivative work inherits license (mistermed virus nature of GPL)
- Linking is considered derivative work in GPL but not in Lesser GNU Public License (LGPL)
-> GNU libc is most prominent LGPLd program
- GPL guarantees the following freedoms (as in free speech, not free beer)
- BSD style licences:
- MIT: Copyright and permission notice must be included in all copies or substantial parts of the Software
- BSD: non attribution provision (contributers names may not be used to endorse or
promote products without permission), advertising clause (removed 1999) - Apache Free License v2: strong branding, contributions become part of licensed work, license terminates if licensee initiates patent litigation
- -> BSD style licenses have no such derivative work clause and thus cannot prevent "misuse" of software (OpenBSD, FreeBSD, NetBSD)
- -> commercial application is usually intended (BSD Unix, X Window System)
- MPL (Mozilla Public License)
- somewhere in between BSD and GPL
- weak Copyleft: MPL source code modified stays MPL, but can be combined with any other code to form a proprietary program
- NPL (Netscape Public License): variant that gives original developer the right to distribute
modifications by other contributers under whatever terms it desires.
- Open Source vs. Free Software
- Open source can be any license acknowledged by the Open Source Initiative (incl. all mentioned above)
- Because of so many licenses all dubbed "open source", check which freedoms they really entail
5.1.5. Alternatives to (kernel) drivers | 1. Denx Training Topics | 5.1.7. Linux kernel / Linux device drivers resources | |||
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