Hey Andras, this is great!  My only request is: can we call them "GUI plugins"?  "startup plugins" sounds too vague for me.  Also, here's a bit more documentation:

http://puredata.info/docs/PdGuiPluginsAPI

Now I'm thinking we should start a "guiplugins" wiki folder section in the doc wiki, so like:

http://puredata.info/docs/guiplugins  (this would be your page, also be called FrontPage)

http://puredata.info/docs/guiplugins/GuiPluginsAPI

http://puredata.info/docs/guiplugins/ExamplePlugins

How does that sound?

.hc