The Linux Foundation has received the most revenue amongst all of the free software and open source non-profits and directly pays its leader the most, but the highest compensation of any sort is still being received by Mozilla Foundation Chair Mitchell Baker, along with her CTO Colleague Brendan Eich.

According to the latest publicly available financial information, the Linux Foundation pulled in just over $9.6 million for their 2010 fiscal year, and after $9.1 million in expenses, generated $537,958 in positive cash flow for the year. In terms of direct salary, Executive Director Jim Zemlin topped out the list with $344,200. Factoring in other compensation, Zemlin brought home $362,904 before taxes in 2010.

But Zemlin is not the highest-paid non-profit leader in the FLOSS community: the Mozilla Foundation generated the highest compensation levels for Baker and Eich who, while receiving no direct salary from the Mozilla Foundation, were compensated $589,953 each from "reportable compensation from related organizations" and "estimated amount of other compensation from the [Mozilla Foundation] and related organizations."

"Related organizations," in this instance, is the Mozilla Corp., the for-profit subsidiary of the Mozilla Foundation that generates much of the Foundation's revenue.

With a revenue of $1,934,659, the Mozilla Foundation ranked fourth of the eighteen FLOSS-related non-profits researched for this report. But with a net cash flow loss of $1,333,815 for the 2010 fiscal year, the Mozilla Foundation was next to last on money lost for the year.

All of this information was obtained from the Federal income tax forms all U.S. non-profits are required to file with the IRS. Specifically, Form 990 (or the 990-EZ when applicable). Thirteen of the non-profits have publicly available information for their 2010 fiscal years, with the other five's information only up to date to their respective 2009 fiscal years.

Given that we're in 2012, why the delay?

Part of the reason is the variations in fiscal years. If these are offset from calendar years, then this would be a reason for the extra time.

Non-profits have an additional reprieve: they can file a Form 8868 and get an automatic three-month extension for filing their returns, no questions asked. And, after that automatic extension, the non-profit can file for an additional three-month extension if they can show good reasons why.

So, this means that the Mozilla Foundation didn't file their 990 until Oct. 5, 2011 with the Linux Foundation filing in just before that on Sept. 31.

Dated as this information is, it paints an interesting picture of the state of non-profits across the community. As a whole, revenue seemed to be on the rise for these organizations and most of them seem to be in good fiscal health, even if they lost cash this year. Combined, the 18 organizations grew just shy of $6 million in assets during their respective fiscal periods.

Another telling piece of information that was obtained from the Form 990s was the "public support" percentage. "Public support," in this context, is the percentage of total revenue that comes in portions that are less than 2 percent of total revenue for the past five years. (The IRS's assumption being that any donation more than 2 percent could skew an organization's non-profit status.)

This percentage does not have to be reported for any organization that hasn't filed five years' worth of returns, nor does it to apply to business trade foundations, such as the Linux Foundation, or private foundations like the Linux Kernel Organization, which gets 100% funding from Google. But for those organizations that reported the public support figure, the Linux Expo of Southern California, Inc. group (which organizes SCALE and the Texas LinuxFest) came in the highest at a 99.68 percent public support figure. The Mozilla Foundation ranked the lowest, with a mere 14.71 percent public support figure--presumably because of the funds coming in from the Mozilla Corporation.

Most of the other non-profits on this list had public support figures in the 80-90 percentage range, with one surprising exception: a 45.3 percent figure at the Software Freedom Conservancy. At least 33.3 percent of funds must come from public support to qualify without exception to be a non-profit, so the SFC is in no danger there. Mozilla, though, has to explicitly state why it deserves to keep its non-profit status under a facts-and-circumstances test, which it does at length in its Form 990.

While this report is meant to be comprehensive, there are some notable omissions of organizations that are active in the FLOSS community. Both the LibreOffice Foundation and the KDE e.V. are based in Germany, and are not subject to U.S. IRS reporting (not to mention the LibreOffice Foundation is still too new to file anything anyway). The Eclipse Foundation, which is based in Canada, is absent for similar reasons.

What follows is an alphabetical listing of the 18 organizations researched, with pertinent data from each organization. The descriptions of these non-profits were provided on the Form 990s themselves, and definitely shed a little light on how these organizations perceive themselves and wish to be perceived. All figures are in US dollars, and all information comes from the Form 990s filed by the organizations for the specified tax reporting year.