Best script for a text-based imageboard?

[Lorenzo]

Does anyone have any recommendations for a text-based imageboard script? (yes, I realize that sounds like an oxymoron) Basically I want something similar to 4chan but without the ability to post images. Some type of archival system would also be nice so that older threads are still readable. Accounts wouldn't be required to post and I'll probably disable them altogether.

Update: I'm considering using Kareha but I can't find any demos online. Also just discovered that they're called textboards rather than text-based imageboards (hence why Google wasn't helping).