Bukkit holds a very powerful API which helps to customize and improve your minecraft-multiplayer experience.
I also develop plugins for it, some were made because I wanted special functions when I played minecraft, some were made for other server-owners.
Want me to develop a custom plugin for your server/community ?
Check out the requirements/needed information here : http://itoobi.de/customplugin
I also got a Bukkit-Dev-Page where all public plugins are uploaded. Approx. 90% of all plugins I ever made are private (I’m not allowed to share them), so you wont find them there.
Bukkit-Dev-Page : http://dev.bukkit.org/profiles/iToobi/
(Some plugins are outdated)