) library containing: a BSD sockets
library, a DNS resolver and an I/O multiplexer that supports select(2), epoll(4) and kqueue(2).
CL implementations on which IOlib has been tested: SBCL, CMUCL, CLISP and Clozure(ex OpenMCL). Probably it works on any implementation supported by CFFI that has native :long-long.
Homepage: http://common-lisp.net/project/iolib/. Download instructions can be found here.
Here is a recent tutorial: http://pages.cs.wisc.edu/~psilord/blog/data/iolib-tutorial/tutorial.html
ASDF-install package (obsolete) http://common-lisp.net/project/iolib/files/iolib-0.7.3.tar.gz