Bukkit

XoXAdmin aims to add a lot of unique, never before seen, powerful administration tools and server customization options.

It combines a number of old private projects I have worked on such as:
Easy Promote (Simple PEX group changing with the most simple commands imaginable)
Custom leave and join messages, fully customizable with colors and PEX prefixes and suffixes.
AutoCalc - a simple yet powerful calculating tool

And many other awesome features currently being worked on.

Easy Promote:
After your entered your rank in the config file, you are basically done.
Now you can promote people simple using the name of the rank as a command. /<rank> <player>
Example: If you want to move the player herp into the group derp, you type /derp herp
Can't get any simpler, can it?

AutoCalc:
If you type any equations ( 1 + 1 , 123 / 321 , 2 ^ 13 ) into the chat, AutoChat will automatically detect it and give you the answer.
No commands required.
You might think, How is this useful?
I personally use this many times a day for checking if my building have the right proportions and many other things.

It also adds unique moderation commands.

/csay <player> <message>
Let's you force the user <player> to say <message> in chat.
How can this be helpful?
The player HerpDerp is bothering you while building.
Send him to the spawn doing "/csay HerpDerp /spawn".

Special Configuration Options.
Customize Leave and Join messages and add certain messages for players.
Add Prefixes and Suffixes to the messages (Permissions EX only)
Example:
If the player Notch joins, you could let the message "OMFG ITS NOT" be broadcasted.