In addition to Steam it's also Linux
You know - the OS that runs all the supercomputers in the world? So of course it has 7 free Office suites, Blender, multitrack audio and video editing, bittorrent, all the popular browsers, virtual machines, fully supports more devices than any other device ever, has an app store with 30 years worth of free apps, can be used to build apps, games and new operating systems and so on.
What it doesn't have? Antivirus 2012 and 3.2 billion other forms of malware. Norton, McAfee, Kaspersky and all of the other $100B/yr parasitic "cleanup after Windows failed" industry. IE. Bing. 37 links to websites you don't want. Crud installed by the OEM for pay. The requirement to log into a Microsoft online account to even fracking install it. Patch Tuesday. Rollback Wednesday. An utter lack of backup tools. Metro. And much, much more.