From Forum Nokia Wiki
Reviewer Approved 
Carbide.c++ supports standard Eclipse plug-ins. That means you can write a normal Eclipse plug-in and have it work with Carbide.c++.
With the release of v1.2 we provide a preliminary API to allow developers access to certain Carbide.c++ features so they can develop plug-ins that can work with Carbide.c++ features.
3rd Party Plugins
Here's a list of some handy URLs to plugins and where to find more plugins than you dreamed existed.
- Context Menu Plugin[1] (only works on Carbide 1.3) - A plugin that shows you explorer context menus in eclipse.
- Logfile Plugin[2] - Really nice tool. Very useful for trailing files like epocwind.out with regexp filtering and coloring.
- Symbian Developer Certificate Request Plug-in [3] - Generate developer certificate requests and manage certificates and keys in this plugin.
- Panic Lookup [4] - Lookup all those confusing Panic codes.
- UIQ 3 Carbide Configuration Plugin [5]
- Beyond CVS [6] - BeyondCVS is a plug-in that enables using Beyond Compare (externally) for comparing files and folders. It also allows comparing a single file to a previous revision in CVS/SVN or Local History.
- Version Control Plugins [7]
- ContextLookup Plugin[8] - A context menu plugin for Carbide and Eclipse that allows the user to search for highlighted words in code and text files on Symbian Developer Network Forums, CPlusPlus.com, Forum Nokia Wiki pages and even Google.
- Hundreds more plug-ins found at Eclipse Plug-in Central [9]
References
In the Carbide.c++ help see the following on writing plug-ins:
- Carbide Help > Carbide.c++ Plugin Developer Guide
- CDT Plug-in Developer Guide