Hacker News Reader

And how much of GitHub is Open???

More than you'd expect, as they've open sourced and contributed to a number of open source projects based on their development of Github.com

Github is a perfect match for MS, both of them are hostile to the idea of Free Software

They open source tools for devs, things like Library's, Frameworks, IDE's etc. Never end products.

They oppose the ethics of Free Software, Open source for them is a way to get free labor

That's not relevant to the discussion of whether or not GitLab is open source.