The International Astronomy Union's Standards of Fundamental Astronomy is a software library providing an authoritative suite of functions useful in astonomonical and geospatial calculations. It is officially available in C and FORTRAN flavours, and there are a variety of unofficial wrappers available in various languages.
The most popular Github project based on SOFA, with a whopping 14 stars, is under the MS Reciprocal License. The readme file also separately includes the text of the SOFA software license. Other projects have chosen, e.g., the MIT license or have simply included the SOFA license with no other licensing declared (e.g.).
I'm new to open source projects, both releasing and including/adapting, and understanding the implications of licensing fills me with anxiety. Especially when it comes to including work such as SOFA which seems, if I'm reading the license right, to be beer-free but not quite free-free.
My question is in two parts:
Are the requirements of the SOFA license (royalty-free use, modification permitted with stipulations) compatible with most/any/some of the fully FOSS licenses, where the SOFA code is included without modification, as in the libraries linked above?
Acknowledging that the SOFA license explicitly states that "
third-party modifications are discouraged", if one were to re-implement some or all of the SOFA functionality natively in another language, would the choice of license this was released in be limited by the SOFA license conditions? I.e., how much freedom can the creators of derived works based on my own SOFA-derived work have?
It's possible I'm worried about nothing, but while I understand code just fine, I don't (yet) understand the fine points of licensing rights and derived works!