Question Answering

Answers Project
A search engine that stores questions and answers submitted by users. This allows for answers to questions to be found instantaneously without having to search a page for that answer.
http://www.answersproject.com

Ask why!
The system answers why-questions by searching for relevant paragraphs in Wikipedia.
http://lands.let.ru.nl/%7esverbern/askwhy.htm

BrainBoost
Question answering engine that accepts natural language queries.
http://www.answers.com/bb/

Helpero
Helps users solve computer related problems.
http://www.helpero.com/

Language Computer Corporation
Includes a demonstration of the company's search technology designed to provide direct answers to simple factual questions.
http://www.languagecomputer.com/

START
Demonstration from the MIT InfoLab Group of its natural language question answering system, developed by Boris Katz.
http://start.csail.mit.edu/