Roam is Roam Research [0] which is a paid web-based product. It's relatively new. There are also some open source alternatives like Obsidian.
Because of it's popularity someone created an org-mode package called org-roam [1] that does some of the things that roam does, but in emacs. These are not officially related though.
I was interested when you mentioned Obsidian was open source, thinking they must of changed that since the last I read about it. But I looked it up again and it's not, it's still proprietary.
Because of it's popularity someone created an org-mode package called org-roam [1] that does some of the things that roam does, but in emacs. These are not officially related though.
[0] http://roamresearch.com/
[1] https://github.com/org-roam/org-roam