SimpSamp
SimpSamp is a statistics library for simple random sampling without replacement. In English, that means it will return a requested number of random elements from a set, without duplicating any of the elements.

For instance, if you have a list of 1,000,000 elements and want 1,000 unique random elements from the list, SimpSamp will do the trick.

SimpSamp implements two algorithms: selection sampling and reservoir sampling, both described in The Art of Computer Programming.

ASDF-install package (obsolete) http://www.thoughtcrime.us/software/simpsamp/simpsamp-0.2.tar.gz