[fcpguru]

good idea, let's build it! The only two others are really:

https://www.xing.com

https://www.angellist.com/

[pluc]

AngelList became Wellfound and is much more startup-oriented than LinkedIn.

There was Otta which went through one of the worst rebranding in recent memory and is now "Welcome to the Jungle".

But beyond that, that's it.