The name of the computer in the movie 2001: A Space Odyssey. Its full name is HAL 9000 and "HAL" stands for a "Heuristically programmed ALgorithmic" computer. Computers in the real year 2001 had nowhere near the speech-articulation HAL does in the movie. To engage computers in extended conversations, programmers need to integrate speech recognition, natural-language understanding, discourse analysis, world knowledge, reasoning ability, and speech generation. DARPA is working on wide-ranging conversational interfaces.