audio plugin

Quick Look plugin to preview contents of installer packages.

Notification plugin for Mail.app.

Mail plugin for OmniFocus.

QT plugin for many media types.

Contextual menu plugin to view DICOM images.

Widescreen Apple Mail Plugin

Autodesk's Maya plugin to import HDR and RAW (DSLRs) image formats

CartLoom us a rapidWeaver plugin to create shopping carts for your websites.

Xfire client implemented as a plugin for Adium.

Spark plugin.