They refer to it at as 'open-core':

https://about.gitlab.com/2016/07/20/gitlab-is-open-core-gith...

I thought this was interesting to re-read in light of this news, so I've resubmitted it for discussion:

https://news.ycombinator.com/item?id=17225725

Good call :) it just went from #13 to #12 on the front page.