While the registry is obviously about the plug-in authors, I figured some of you might wonder who's running this thing. So, my name is Ingo Lütkebohle, I'm currently a PhD student in robotics and I've been running the registry, in one form or the other, since 1996 when I was working as a software developer and network engineer. Together with a couple of friends, I still run a server and so can provide a place for the registry to live (which I will do as long as I can and people want me to, so for quite some years to come, probably ;-). I still use The GIMP regularly and now do computer vision for work -- my interest in that is in no small part due to my earlier experiences with the GIMP, so I still have a sweet spot for this tool. I hope you enjoy the Registry!
Cosm is an integrated collection of extensions to Max/MSP/Jitter to assist the construction of navigable, sonified, complex virtual worlds, and has been designed to facilitate use in CAVE-like environments.
DrawPile is a sketching oriented drawing program with a twist: you can share your drawing live with other users. There are no restrictions on who may draw where; every user has full access to the whole picture simultaneously.
Gimphoto is GIMP modification with new menu layout, great selection of plugins, and many additional resources for more professional look and feel as digital photo retouching and image editing application package.