Looking at the screenshot I thought "Wow, I can see why Github would be annoyed at that" before realising that was their proposed not-at-all-like-github-now-honestly new UI.
Their demo looks like they just stole Github's CSS templates.
Open source covers the copyright. This is more a trademark issue. The trademark issue is independent of the copyright-openness of their assets, as it is not valid to infringe their trademark either with their assets, or with fully copyright-independent assets.
This is correct and highlighted by the fact that Github doesn't focus on the CSS at all -- their claim would have been exactly the same if they did not copy anything and wrote everything from scratch. It's about trademark and user confusion, not copyright.
Well, this reminds of the Microsoft Office UI (I think its called Ribbon?). I think the rule around that is that people can make apps that mimic that UI EXCEPT in the case where the apps are direct competitors. Seems to be the case here too.
Yeah, you could easily think you were looking at Github. I think it would be polite of them to change it a little bit more. Also, while it's natural for them to want to have a link to their Github account in the header of their site, as it is now (in combination with the extremely similar look) it almost makes them look like they are affiliated with Github.
Yea, Gitlab and Bitbucket are pretty significantly different in look. Although those two were commercial entities that probably had the foresight to think about these issues.
Gitbucket looks like it's independent devs just trying to create a clone in Scala. It would be pretty cool to have a github alternative in scala :-)
They also don't overtly describe themselves as Github clones. Slightly different goals: one tries to compete and aims to offer something superior, the other is intentionally a cheap knock-off (not intended to sound derogatory - there's a place for that).
Really any website that uses one of the major CSS templates (bootstrap, etc) looks pretty much the same. I see a dozen websites a day that all have the same fonts, button styles, layout, etc.
Their demo looks like they just stole Github's CSS templates.