ATTENTION!
kusaba has been discontinued! Further support for kusaba will not be offered by its official creator, however if you absolutely need support you can contact those who have continued the development.
If you wish to continue to use software which is supported and actively being developed by the same author, please visit one of the following:
PHP
http://code.google.com/p/tinyib/
Python
http://code.google.com/p/pyib-standalone/
If you would like assistance in this process, or have any questions about PyIB or TinyIB (not support on fixing your current kusaba installation) contact tslocum@gmail.com through e-mail or Google Talk.
kusaba is modular imageboard software, written in PHP, and with database abstraction by ADOdb Lite. It requires only one installation for an entire website, with as many boards as they wish. It also supports user-created modules which can be created and distributed among installations, adding functionality to the already robust software.
To learn about imageboards, see Wikipedia's take on it.