When comparing Guile vs Kawa, the Slant community recommends Guile for most people. In the question“What are the best scheme implementations?” Guile is ranked 2nd while Kawa is ranked 7th. The most important reason people chose Guile is:
Guile makes it easy for users of your application to write extensions without needing to understand the plumbing of your program.
Specs
Ranked in these QuestionsQuestion Ranking
Pros
Pro Easy to customize and extend applications
Guile makes it easy for users of your application to write extensions without needing to understand the plumbing of your program.
Pro GNU's official extension language
Chances are a system running enough GNU software will already have it installed.
Pro Excellent documentation
The documentation provides conceptual overviews, tutorials, and a detailed reference for all commands, functions, and operators.
Pro Fantastic interface to C, C++ in both directions, embedding guile in C/C++ and embedding C/C++ in guile
Pro Java interop
Kawa runs on the JVM and can use Java libraries.
Cons
Con Weak copyleft
LGPL