Sponsors
Why the sponsors? I thought it all ran on goodwill?
The Apache Software Foundation may formally end development of the long-in-tooth 1.3 and 2.0 branches of its Apache HTTP Server to focus support on the 2.2.xx branch. Apache is the most popular HTTP server software in use on the web, with numerous machines still running branches 1.3 and 2.0. However, developer interest for the …
You get goodwill for these sponsorships. And the goodwill of such a major force as Apache is clearly worth something to these companies.
In some cases it's two-way: for example, Google sponsors Apache, and Apache participates in Google's "summer of code". But the two are not connected. In a case like Microsoft, one can only suppose they're keen to build bridges to developer communities that are not hostile to them (Apache being explicitly vendor-neutral).
Oh, and your article, like all the others, is only part of the story. Whereas Apache 2.2 is alive and has developer interest, there's a whole lot more in the nascent 2.4.
And you can still get support for 2.0 and even 1.3. I did some work for a client using 2.0 as recently as last November! But I wouldn't do that unpaid, unless there was a very compelling reason.
You get to file bugs and patches against ASF code. Actually, you can do that anyway. Facebook are already big users of/contributors to Apache Hadoop; they use PHP as the front-end, which may run on Apache Httpd -I don't know.
The sponsorship helps pay for the infrastructure apache uses: SVN, the EU mirror, the web servers, bug tracking, wiki, the Hudson CI server etc. Yahoo! host some Hudson server(s) which is used to help build and test Hadoop and other builds.
What do you gain then? Publicity, goodwill. And by helping keep the ASF's infrastructure alive, they know that the stuff they depend on will still be there, will still evolve. It's still way cheaper than buying oracle licenses for 16 petabytes of data.
The other way that a lot of these companies contribute is by having full time staff working on things. Some projects: all end users, all just solving problems together. others have startups behind them. For the datacentre-scale platform of Hadoop and its friends, which is Line-of-business critical to Facebook as well as yahoo, you can be sure that not only do they have FTEs working on bits of it, they spend a lot of time testing new releases on their infrastructure.