I am currently working on my own IRC client called "PlugIRC" which is basically a user-interface widget written in java which shall support Swing, SWT and Windows Forms (via J#). Apart from multiple server-connections and multiple channels in a tab-based layout, it will support "plugins" to automatically intercept and send messages.
Once this is finished, DocSynch has a better future in Eclipse and Visual Studio .NET. And the current IRC plugin for jEdit will be replaced (or updated to 3.0), too. Stay tuned!