OpenCola is a brand of open-source cola, where the instructions for making it are freely available and modifiable. Anybody can make the drink, and anyone can modify and improve on the recipe.
The original version 1.0 was released on 27 January 2001. Current Version is 1.1.3. Although originally intended as a promotional tool to explain free and open source software, the drink took on a life of its own and 150,000 cans were sold. The Toronto-based company Opencola founded by Grad Conn, Cory Doctorow, and John Henson became better known for the drink than the software it was supposed to promote. Laird Brown, the company's senior strategist, attributes its success to a widespread mistrust of big corporations and the "proprietary nature of almost everything."
(Source: English Wikipedia; text licence: CC-BY-SA)