What are plugins? Plugins are extensions to the Dita-OT code that add or modify functionality.  Although plugins are often used to add specializations to the Dita-OT, they can also be used to simply override processing logic for standard elements.  This allows users to customize the logic of the system without actually changing the code in the Dita-OT installation. In many cases, plugins can be carried over to an upgraded version of the OT and still run properly. 

Contributed open-source plugins. Download any of these plugins into the /demo directory of your DITA-OT installation and unzip them there. That's all you need to do for a plugin.

Contributed plug-ins at SourceForge. The FO plugin, the FrameMaker adapter, CSHelp, and the new IBM Troubleshooting plugin are here.

Contributed plug-ins at Yahoo! dita-users group. You will find the tocjs plugin here, along with an index term extractor, an improved htmlhelp transform, and a simple search engine.

Creating a plug-in for the Open Toolkit.

See Design:Create Plug-in Architecture and related Development Documents on SourceForge

See parts 14-17 of Robert Anderson's tutorial on on Extending the DITA Open Toolkit presented at the Silicon Valley DITA Interest Group November 2007 by Robert Anderson, IBM Chief Architect of the DITA Open Toolkit.