The Alfred P. Sloan Foundation will give $3 million to the Wikimedia Foundation to help improve the quality and reach of Wikipedia.
The organization announced the gift this week and said it would be disbursed evenly over the next three years.
Doron Weber, Sloan program director for Universal Access to Recorded Knowledge, called Wikipedia "the largest encyclopedia in human history and one of the top 10 Web sites in the world.
"Wikipedia represents a quantum leap in collecting human knowledge from diverse sources, organizing it without commercial or other bias, and making it freely available to people everywhere," Weber said in a statement.
The grant will help support a new software feature that will allow experienced editors to grade the quality of articles. Wikimedia said the labels, or "Flagged Revisions," would be akin to nutrition labeling.
Wikimedia also plans to use some of the money as it expands outreach through programs and events like Wikipedia Academy. The academy promotes contributions from academics and other targeted groups, while teaching them how to contribute to the online encyclopedia.
The Wikimedia Foundation also announced that it hopes to distribute educational tools from Wikipedia and similar projects through DVDs and books to reach people without Internet access.
Wikimedia representatives said the Sloan grant comes at a critical time when their foundation is settling into new offices in San Francisco and increasing its support staff from 10 to 15 people. The number of employees is expected to grow to 25 by 2010.
Wikimedia reported an operating budget of $4.6 million for 2007-2008, with 57% of the spending supporting technology.
Sue Gardner, executive director of the Wikimedia Foundation, said the foundation "operates on a shoestring, unable to pursue partnerships, execute projects, or even to effectively fundraise.
"This institutional support from Sloan will enable us to make progress on some key goals: increasing quality, broadening participation, and distributing free knowledge to people without Internet connectivity," she said in a news announcement.