[ mona / prog / sol ]
I am using bbs.jp.net but apparently there are many others.
Also, where did you hear about SchemeBBS?
Out of all places I came here from 4chans /jp/; Which is a literal shithole these days.
Saw it being mentioned on sageru and some /jp/ spinoffs, I don't remember where I heard about it first. I connect via textboard.org.
I think I heard about it on lainchan.
Just stumbled upon it from another textboard (forgot what it was called, it's likely dead now.)
textboard.org its easy to remember
I found it when searching for textboards other than danger/u/.