Although the project has been idling in the back of my head for a while, it only really started when I realized it was possible, thanks to the script found here. I had never contributed to KDE before and felt this was a project I could tackle, but when I tried running it I ran into lots of problems, so many in fact I believed it would be easier just to start fresh in a KDE 4 environment.
Although the stated goal is full compatibility with GreaseMonkey scripts, I must admit I have doubts about the feasability of such a project. Because the original GreaseMonkey script is written in JavaScript it is much closer to the code than our C++ version. Also, many popular userscripts use XPath, which is not available yet in Konqueror/KJS.
The other worry is my KDE/coding skills. As I said before this is my first contribution to KDE so I am not sure I understand all of the internals of KHTML, KJS and Konqueror to allow everything that is possible in GreaseMonkey, especially the cross-site XMLHttpRequest object and the unsafeWindow object... (Think you can help? Please get in touch).
But even if I never manage to get everything working, I still believe that a plugin that allow arbitrary JavaScript to run on a given webpage is still way-cool :) Right now it is already possible to run custom scripts that will run in certain sites according to includes/excludes (regular expression) rules. Here are some early, sample screenshots:
I started working on this plugin in January but gave up, mostly because I couldn't keep up with the kdelibs API breakage every Monday! Now that things are a bit more stable I picked up development again. I have received offers for help so I thought importing it early into playground would be a good thing to gather interested developers. Hopefully it will be good enough to move to kdeaddons before the deadline, if not then it will be a nice new feature for 4.1 :)
Thanks for the interest, hopefully in a few weeks I'll have more complete/interesting things to show.