Licensing

• An overview of terminology and categories of software licenses

• Free software - permission for anyone to use, copy, and/or distribute, either verbatim or with modifications, either gratis or for a fee.
  • GPL GNU General Public License - original example of a free software license; most widely used.
  • Apache License 2.0
  • FreeBSD License
  • Microsoft Reciprocal License
  • FSF free software list

• Copyleft software - free software whose derivatives and copies must also be distributed as free software.

• Non-copyleft free software - Free software whose license allows derivatives to be turned into proprietary software.

• Public domain software (with source code) - not copyrighted. Can be used as free software, but can also be turned into proprietary software.

• Open source software - more or less the same collection of programs as free software with some exceptions.

• Proprietary software = non-free software
  • Generic EULA
  • Windows XP Home Edition EULA

• Freeware - generally refers to software that is distributed free-of-charge, usually in binary. Not the same as free software.

• Shareware - allows users to share applications with others, but it does not include the source code and usually requires users to pay a fee if they continue using it.