Collected Algorithms of the ACM (CALGO) <http://www.acm.org/calgo. This site has information about the software associated with papers published in the Transactions on Mathematical Software (TOMS) which are available in print and through the ACM Digital Library. This software is refereed for originality, accuracy, robustness, completeness, portability, and lasting value. (source: Home page). Until December 2004, CALGO was also published in loose-leaf form, but this has now ceased. The associated free website will continue to be maintained and updated.
The Stony Brook Algorithm Repository
<http://www.cs.sunysb.edu/~algorith Professor Steven S. Skiena has mounted this site, based on his book with the same title, "to serve as a comprehensive collection of algorithm implementations for over seventy of the most fundamental problems in combinatorial algorithms" (source: Home page).