The Dictionary of Algorithms and Data Structures (DADS) is an online, publicly accessible dictionary of generally useful algorithms, data structures, algorithmic techniques, archetypal problems, and related definitions. In addition to brief definitions, some entries have links to related entries, links to implementations, and additional information. DADS is meant to be a resource for the practicing programmer, although students and researchers may find it a useful starting point. DADS has fundamental entries in areas such as theory, cryptography and compression, graphs, trees, and searching, for instance, Ackermann's function, quick sort, traveling salesman, big O notation, merge sort, AVL tree, hash table, and Byzantine generals. DADS also has index pages that list entries by area and by type. Currently DADS does not include algorithms particular to business data processing, communications, operating systems or distributed algorithms, programming languages, AI, graphics, or numerical analysis.