Software License

SCEC scientific software is typically licensed under the Apache 2.0 software license.

Overview of Apache Licensing Conditions

• Apache License 2.0

Like any free software license, the Apache License allows the user of the software the freedom to use the software for any purpose, to distribute it, to modify it, and to distribute modified versions of the software, under the terms of the license.

The Apache License, like most other permissive licenses, does not require modified versions of the software to be distributed using the same license (in contrast to copyleft licenses). In every licensed file, any original copyright, patent, trademark, and attribution notices in redistributed code must be preserved (excluding notices that do not pertain to any part of the derivative works); and, in every licensed file changed, a notification must be added stating that changes have been made to that file.

If a NOTICE text file is included as part of the distribution of the original work, then derivative works must include a readable copy of these notices (again, excluding notices not pertaining to any part of the derivative work), in at least one of three places: within a NOTICE text file distributed as part of the derivative works, within the source form or documentation, or within a display generated by the derivative works (wherever such third-party notices normally appear). The contents of the NOTICE file do not modify the license, as they are for informational purposes only, and adding more attribution notices as addenda to the NOTICE text is permissible, provided that these notices cannot be understood as modifying the license. Modifications may have appropriate copyright notices, and may provide different license terms for the modifications.

Unless explicitly stated otherwise, any contributions submitted by a licensee to a licensor will be under the terms of the license without any terms and conditions, but this does not precede any separate agreements with the licensor regarding these contributions.

Software License Summary

• http://en.wikipedia.org/wiki/Comparison_of_free_software_licenses

Differences between open software licenses tend to rest on a few primary issues including:

• Type
  • Source Code Visibility
  • License Restrictive or Permissive Use
  • Clauses in License Text
  • Description

• No license
  • Open
  • None
  • 0
  • Without a license, the code is copyrighted by default. People can read the code, but they have no legal right to use it. To use the code, you must contact the author directly and ask permission.

• Public domain
  • Open
  • Permissive
  • 0
  • If your code is in the public domain, anyone may use your code for any purpose whatsoever. Nothing is in the public domain by default; you have to explicitly put your work in the public domain if you want it there. Otherwise, you must be dead a long time before your work reverts to the public domain.

• GPL License
  • Open
  • Copyleft
  • 12
  • The archetypal bearded, sandal-clad free software license. Your code can never be used in any proprietary program, ever! Take that, capitalism!

• LGPL License
  • Open
  • Mostly Copyleft
  • 16
  • GPL with a cleverly-constructed pressure valve release. Your free software can be binary linked to proprietary programs under certain very specific circumstances.

• BSD License
  • Open
  • Permissive
  • 2
  • Short and sweet. Includes legal disclaimer of liability with explicitly named organization.

• Apache License
  • Open
  • Permissive
  • 9
  • Requires derivative works to provide notification of any licensed or proprietary code in a common location.

Further Information

• Wikipedia Descriptions of Apache License 2.0
• Main SCECpedia Wiki