Amy Vernon (@AmyVernon)

Update: See this post about the “unknown” and “other” categories in the stats below.

It’s clear who has won the OS wars: The user.

Just a few short years ago, Apple computers were little more than afterthoughts outside of artists’ circles. They certainly were not the go-to computers for anyone serious about programming or software development. That was left to the Windows and Linux users.

At conferences, on Sourceforge, and in other open-source communities, the OS battle to be fought was clearly Windows vs Linux. Those who liked Microsoft could call upon the massive numbers of users. Those who preferred Linux could hold themselves up as the true standard-bearers of open source.

You would not have shown your face at, say, ApacheCon, with a MacBook.

In conversation with none other than SourceForge’s new Community Growth Hacker, Rich Bowen (from whom I shamelessly stole the opening sentence of this post), it’s clear the open source community has matured to the point where the platform matters little – it’s the product, the result, that’s important.

We combed through about two years’ worth of data on SourceForge, looking at the platforms of the users who downloaded projects, and millions more Mac users are downloading open source projects now than were in February 2010. In the same time, Windows downloads have increased by a much smaller percentage and Linux downloads have actually declined.

And let’s not forget those in the “other” category where the operating system of the folks who downloaded was unknown:

There were a few data points I found especially interesting, though a bit puzzling: April appears to be a slow month for downloading software on Sourceforge. If you look at all platforms, for each year, there was a significant dip in downloads.

Why? Perhaps it’s Spring fever. Given the fact that it’s an across-the-board dip two years running has some statistical significance. We’d need more information – and data from more years – to determine just what that significance is, though. I’d love to hear theories from readers in the comments, though.

A column on oStatic last year dissected the complex relationship Apple has had with open source, and pointed out how it made sense that Apple both used open source in its operating system and contributed code back to the community.

Apple isn’t big enough to control the programs people will use on their computers, the author pointed out, so the best alternative was to help ensure no one could, as Microsoft very nearly did in the 1990s. Helping keep the open source community robust helps prevent another near-monopoly like Internet Explorer was in that decade.

The Sourceforge downloads data aren’t the only stats that show the rise of the Mac in open source.

Evans Data Corp. this summer released a survey that showed Mac had surpassed Linux as a development platform. The survey, conducted in June, was of 400 professional software developers. While developers are still targeting Linux for development more than Macs, they’re using Mac as the actual platform more.

The developers are increasingly making their software good across multiple platforms, too. A good deal of Sourceforge downloads are on two, three or more platforms.

A cursory survey showed that most projects downloaded primarily for one or two platforms appeared to be much more utilitarian than those downloaded on all three platforms.

Projects such as TortoiseSVN and WinMerge are popular with Windows users. iTerm is popular with Mac and Linux users, enabling the setup of a Mac terminal emulator. Fink, naturally, is downloaded by Mac and Linux users, as it eases the integration of open source projects into their Mac and Darwin environments. X-Chat Aqua brings IRC to Mac and Linux.

An exception to this trend appears to be Linux users, who love downloading UTube Ripper, which allows them to download YouTube videos and convert them. Not altogether surprising that Linux users bucked the trend, though, given that common sense would say they’re much more likely to seek out open source for most of their software needs.

On the flip side, many of the programs downloaded regularly by users regardless of platform tended to be more for alternatives to expensive proprietary software and therefore more useful to a wide variety of people.

Projects such as Audacity for audio editing, Gimp (Windows and Mac versions) for image editing, Sweet Home 3D for virtual interior design, Celestia for 3D visualizations of outer space and Hugin for panorama stitching and processing showed up as big downloads for Microsoft, Mac and Linux.

What will be an interesting statistic down the road will be where iOS and Android downloads start increasing. As tablets grab hold of more of the market, more open source projects will be made available for those OS and the smartphone OS – of which Apple and Android are the most common. No doubt, some of the downloads in the “other” category are for those OS.

It’s heartening to see so much diversity in the open source community – the idea behind open source is, after all, freedom of choice.

Amy Vernon was a professional newspaper journalist for 20 years before working as a freelance writer and consultant for a variety of publications. She has covered open source for the enterprise for Network World and consumer technology for Hot Hardware, among other sites. She uses Adium, Open Office, NeoOffice, Sea Monkey and other open source programs on a near-daily basis.