I assume you are talking about Common Lisp; Clojure clearly does not suffer any issues with library availability, since it can utilize and interact with any Jav

I assume you are talking about Common Lisp; Clojure clearly does not suffer any issues with library availability, since it can utilize and interact with any Java class. That being said, most of the CL implementations I know of have some sort of FFI that can be used to invoke functions written in at least one other language. Finding a C implementation or library is not so hard for most things; using the FFI is a bit painful sometimes, although grovelling tools can help. Also, where it counts, there certainly are Common Lisp libraries -- XML, SQL databases, GUI, distributed/parallel programming, various mathematics, etc. all come to mind.