When comparing Guile vs Hy, the Slant community recommends Guile for most people. In the question“What are the best Lisp dialects?” Guile is ranked 4th while Hy is ranked 8th. The most important reason people chose Guile is:
Chances are a system running enough GNU software will already have it installed.
Question Ranking
Pros
Pro GNU's official extension language
Chances are a system running enough GNU software will already have it installed.
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 Excellent documentation
The documentation provides conceptual overviews, tutorials, and a detailed reference for all commands, functions, and operators.
Pro Python interop
Hy compiles to Python's abstract syntax trees. Python can import Hy modules, and Hy can import Python modules.
Pro Easier to read
Distinguished between arrays (or vectors) and function calls by using [] and (), respectively.
Pro Copyfree and open source
Uses the MIT (expat) license.
Cons
Con Weak copyleft
LGPL