Port25

Port25 is the website of Microsoft's Open Source Software Lab (OSSL). The website is named Port 25, after the SMTP port. Microsoft OSSL claims to be "located on the company’s main campus, the lab houses more than 300 servers, which collectively run more than 15 versions of UNIX and 50 Linux distributions." Recently launched, Port25 has attracted a large number of comments. Take for example, an article on explaining Microsoft's Open Source Software Lab (Part 1), has comments ranging from NetBSD is not a linux distro (contrary to wide the author writes), and also CentOS & NetBSD being "lesser known" distros, and half-positive comments such as:

I'm so happy to see Microsoft "trying" to get a glimpse of what Open Source is, because after all the censoring they've done, and the copyright laws they've created to try to stop users like us that love GNU/Linux from using it, they had to use something without paying for it. I'm pretty sure that those 300 servers with those 50 distros has been the cheapest investment ever.

There is also another post on why is it called Computer Science.