The foundation created by Google co-founder Sergey Brin and his wife, Anne Wojcicki, has given a $500,000 grant to help Wikipedia fund its $28.3 million annual budget. Wikipedia holds an annual fundraiser instead of accepting advertising—you may have seen "A personal appeal from Wikipedia founder Jimmy Wales" if you've used the online encyclopedia this week.

The $500,000 grant comes from the Brin Wojcicki Foundation and goes to the Wikimedia Foundation, which began its annual fundraiser two days ago to support Wikipedia and sister sites. Wojcicki, who married Brin in May 2007, is the founder of personal genomics company 23andme. (Google has also given millions to Wikimedia in the past.)

While the donation is a serious one (though the Stanton Foundation recently gave $3.5 million), it's far from enough to take care of all Wikipedia's annual expenses. The Wikimedia Foundation's total planned spending is $28.3 million in the 2011-12 fiscal year. Last year's campaign raised $16 million toward the foundation's $20 million budget. The latest fundraiser will extend through January.

"If everyone reading this donated $5, our fundraiser would be over today," a message on Wikipedia said, while noting that the site had raised $657,000 toward its "Friday goal" of $1 million. Wales, who founded Wikipedia in 2001, likens the user-created encyclopedia to "a library or a public park a temple for the mind."

"Google might have close to a million servers," Wales writes. "Yahoo has something like 13,000 staff. We have 679 servers and 95 staff. Wikipedia is the #5 site on the web and serves 450 million different people every month—with billions of page views. Commerce is fine. Advertising is not evil. But it doesn't belong here. Not in Wikipedia."