Conversation

The main issue with Common Lisp is the degree of fragmentation. Every CL library is the result of a lone hacker's efforts and is therefore only 80% finished and was abandoned soon there after. There's also this odd unanimity around Emacs/SLIME as the editor/IDE of choice for CL.

Clojure seems to be somewhat more adapted to the 21st century developer ecosystem, but it has problems of its own, including the fact that Java itself is kind of old hat at this point.