SIMBL is the SIMple Bundle Loader.

It enables various plugins like PithHelmet to run in Cocoa applications such as Safari.

Bugs

If you think you've hit a bug, check the FAQ. If you're question hasn't been answered there, peruse the Issues List.

History

You can follow NewDevelopments for semi-interesting information about SIMBL. There are some enhancements scheduled for the near future. The brave can try and make sense of the change log.

Plugins

There are a number of SIMBL plugins to enhance a number of applications.

Development

For more information about developing plugins that use SIMBL, you can try following the tutorial. You could also skip to the troubleshooting section.

If you are interested in modifying a particular Cocoa application, the Armchair Guide to Cocoa Reverse Engineering.