The FriCAS Library contains over 1,000 strongly-typed mathematical domains and categories. It is written in Spad. The source code for the library is here:

https://sourceforge.net/p/fricas/code/HEAD/tree/trunk/src/algebra/

These files are part of the standard distribution, you get them if you download FriCAS Sources.

See also FriCAS Algebra, FriCAS Library Examples.