NIST - Dictionaries of Algorithms and Data Structure
This is a dictionary of algorithms, algorithmic techniques, data structures, archetypal problems, and related definitions. Some entries have links to implementations and more information. Click here to access the dictionaries.
ACM Collected Algorithms
The source, ACM Collected Algorithms (CALGO), is "refereed for originality, accuracy, robustness, completeness, portability, and lasting value." All the algorithms could be downloaded from the Collected Algorithms site.