Microsoft is more and more cloud and services, but they still have a developer mentality and they have done some good stuff with open source lately.
If someone is going to buy Github, Microsoft is probably the most friendly to developers. Unless Google or Facebook wants to go full altruist and buy for the credibility.
A lot of people would say Google these days... now that they're starting to move beyond Material Design 1.0 a lot of their products are becoming more visually mature and unique, along with their substantial investment in machine learning to make their software more personalized, etc.
Every time I run into an issue with Atlassian software, I find a JIRA ticket from 7 years ago. If they have a capable dev team, it's probably working on projects off my radar?
Examples include Apple, most of the enterprise hardware space, IoT/wearables, *aaS, the top 10-100ish cloud vendors, etc.
Even Microsoft is a hardware company now.