TrueKnowledge

TrueKnowledge is a semantic search engine combining natural language processing, internal knowledge base and external databases for generating answers to the users’ questions. It stores the knowledge in a form that computers can understand. It can answer the questions in natural language (English). TrueKnowledge does not only offers some web pages where you can find the answer, but it also provides exact answers to your questions. For example, I tried the following questions and I received clear answers amazingly.

* What is the Semantic Web? TrueKnowledge: the Semantic Web, an extension of the World Wide Web in which facts can be tagged within documents to allow machines (as well as humans) to extract information from them.
* What is the time in Istanbul now? TrueKnowledge: March 13th 2010, 16:24:06 EET
* How long is the flight time from Istanbul to San Francisco? TrueKnowledge: 14 Hours
* Is Jennifer Lopez single? TrueKnowledge: No (It is just an example. I don’t care about the answer =)) )

For some questions TrueKnowledge exposes how it finds the answer by listing the facts that the engine used for providing the answer. You can see them by clicking “How do we know this?” link at the bottom of the answer frame. Also, there is a real-time counter on the web page of TrueKnowledge which indicates the number of facts and things that the answers are based on.
TrueKnowledge allows the users to contribute the knowledge by rating and editing the answers. Furthermore, you can add your own answer to a certain question.

You can try it from here. Also, there is a Mozilla plug-in which enhances your Google searches by adding TrueKnowledge’s answer to your search result.