Iris
Iris is a command-line based forum software. If you've ever used a BBS in the past, you'll fine this interface quite similar to forums of that style. Not quite as complicated as bboard.
Usage
To use iris, once logged into your shell account, just type iris.
Once there, type t to see the topics. To read a topic, just type the topic number. To reply, r followed by the topic number.
To quite, just type q.