Well, we already knew that Google was a big funder of Mozilla and its various offshoots (some Mozilla press events have taken place at Google's London offices), but 85 percent?
That seems to be the conclusion to draw after Mozilla released its 2006 financial statement, including this note: "Mozilla has a contract with a search engine provider for royalties. The contract originally expired in November 2006 but was renewed for two years and expires in November 2008. Approximately 85 percent of Mozilla’s revenue for 2006 was derived from this contract."
Over to the blog of Mozilla chief Mitchell Baker, and "the vast majority of [our] revenue is associated with the search functionality in Mozilla Firefox, and the majority of that is from Google."
So there you go - almost all of Firefox etc's money comes straight from Google.
Credit to the Register for adding up this particular pair of twos.