Stockepedia is an online Encyclopedia of the Stock Market. It's unique because it's created by the investing community, for the investing community, and it's completely free to use. Anyone can contribute and add to the content. The idea is that everyone who uses Stockepedia will have an "information-advantage" over those who don't, and therefore an "edge" in the stock market.
It offers semi-realtime quotes of NYSE stocks. Whether it plans to cover other stock exchanges as well is unclear.