They used to exploit their dominant market position to replace de-facto standards with their own: kerberos "extensions", creating ActiveX instead of just implementing NPAPI, removing JNI from the MS JVM. But they can't do that any more. They lost too much ground under Ballmer.
Now they're nearly tripping over themselves promoting their cross-platform tolerance. Run Linux in our cloud! Run our apps on all the platforms! Sync/connect our apps/devices to any service!
Source: Age 34, started with Linux in '97 (Slackware 3.2)