As I said before, I'm currently playing around with Kate. I must say I've learnt a lot in this week. I was able to compile my own little plugin, wrote it from scratch (referring to the helloworld code of course!). It doesn't do anything interesting right now, but I plan to make it do something cool.
The idea is to listen on a TCP socket and insert whatever data I receive on that socket. I have no idea right now where this code should go. I can make a standalone server easily, but integrating that into the callback based model of a GUI system might be pretty tough. I am also reading up on C++, and plan to start with Telepathy next week. I should probably also mention what exactly I am doing when I debug Kate: (from within the build directory)
$ make
$ make install
$ ../run.sh kate 2>&1 | grep <my-debug-prefix>
The '2>&1' part means that the stderr is redirected to stdout. That's how I can grep :) I assumed that I won't have to run CMake everytime. Also, it's becoming really tedious, using vim and shell all the time. I will have another go at setting up the whole thing with QtCreator, I might even get to learn something in the process!