Alfred Van Hoek's REALbasic Plugins
Many REALbasic Plugins, including RBPluginPlunger, HTMLRendering and other great plugins
Building REALbasic plug-ins with MPW
A kit for building REALbasic plug-ins with Apple's free MPW. Uses REALBasic Plugin SDK 4.5a1 and later.
Valentina for REALbasic
Create fast and powerful database driven applications using REALbasic. It allows to drag easy to access classes of object-relational database directly into REALbasic project. [Shareware]