NOTE this is now the zooToolBox, which contains just about every zooTool ever released and more. the full list of goodness that comes in this package is quite extensive but includes:

• curve constraints
• stretchy IK spine
• registration tools
• pose to slider tool
• animation library, full support for icons, anim/pose clips, incremental apply etc...
• align tools
• bolt on ik
• proxy ik
• dynamic parenting tools
• camera management tool for in scene cutting between multiple cameras
• renaming tools
• trigger tools
• viewport trigger authoring tools
• reorder attribute tool

and many more...