Microsoft's recent behaviour could represent a genuine change in corporate culture, and I sincerely hope that it does.<p>But, spending a little cash to have a LF sponsorship to point to, and talking up open source and switching development of some peripheral products to that model now that they've figured out how it can be good for them doesn't really mean much.<p>We've had 30 years of the old Microsoft, where free software was cancer, a joke, and Microsoft used all its corporate power to try to strangle Linux (especially) as a possible competitor.<p>You'll notice that today, Windows, Exchange, Office, Azure, etc, etc, -- all the products that they make money from are still totally, or almost totally, proprietary. There's clearly been a recognition that open source is not going away, and even has some value, but they haven't actually changed to being a genuine open source company.<p>GitHub was always a risk: one day it was going to be acquired (pre- or post-IPO). Clearly others (eg. Oracle) would be worse than Microsoft, but I think some level of concern (especially given the Skype debacle) is warranted.