The external hyperlinks given below list contributors who have converted the original SOFA library into other forms. They have undertaken to make them freely available and to provide support for their implementation.

These implementations, or indeed any others, are not endorsed by the SOFA Board or the International Astronomical Union. The Board do not exercise any editorial control or perform any validation of the information you may find at these locations nor do they accept responsibility for loss or damage arising from the use of information on these sites.

LanguageInformation and source URL'sJavaA pure Java translation of the SOFA software by Dr. Paul Harrison from the Jodrell Bank Centre for Astrophysics at the University of Manchester, downloadable from:

• http://javastro.github.io/jsofa/

CEssential Routines for Fundamental Astronomy (ERFA). This is a copy of the ANSI C version of the SOFA library but with "iau" removed from all function names and re-licensed to be compatible with typical Free/Open Source Software licenses (n.b. it is no longer read-only and therefore changes may be made by anyone). It has been produced by the AstroPy group (project page) and it may be downloaded from the GitHub repository:

• https://github.com/liberfa/erfa/releases/

C#World Wide Astronomy (WWA) library. This is a set of C# algorithms and procedures that implement standard models used in fundamental astronomy derived from the SOFA software collection. The WWA library uses different function names (prefixes) and C# language specific modifications as required by the SOFA license. It was written by Attila Abrudán and may be downloaded from Github:

• https://github.com/abrudana/wwa

• https://github.com/abrudana/wwa/releases

JuliaJulia Library. Astrometry.SOFA is a pure Julia language implementation of the SOFA software library by Dr. Paul Barrett of The George Washington University. The SOFA subtle is a drop-in replacement for the Julia packages SOFA.jl and ERFA.jl, which are wrappers of the respective C libraries. The SOFA subtitle is included in the Astrometry.jl package. Documentation can be found at:

• https://barrettp.github.io/Astrometry.jl/dev/

C#AstroRoutines C# library. AstroRoutines is a C# port of the SOFA software library created by Alex Man (Starsbane), with "iau" removed from all function names. Just like the original SOFA software library, each release of passed all unit tests. This is a .NET Standard 2.0 library compatible with .NET Framework 4.6.1+ and AstroRoutines .NET/.NET Core 2.0+. This library can be downloaded from:

• https://github.com/starsbane/AstroRoutines

• https://github.com/starsbane/AstroRoutines/releases

• https://www.nuget.org/packages/AstroRoutines/

If you have an implementation of the SOFA library that you wish to have listed here, please contact the SOFA Board.