[Mackx]

Originally Posted by MrWarper

Yes, I downloaded everything from there just in case it disappeared with iRex and started already to leaf the manual. Is there any use for the stuff under the "3.0" directories? Anything else needed to start fooling around (besides a real or VM Linux system with all the stuff in it)?

You can look at the older stuff (i.e. 1.7) for the pdf-plug-in based on the poppler library. In 1.7 pdf was a public plug-in and mobi was the 'private' plug-in with DRM.
The iOn Development Environment.pdf is an important document to start with, but you probably discovered that already.

Originally Posted by MrWarper

OK, so if I want to do anything with PDFs, either I write a standalone application or a new PDF plugin from scratch, right? Dammit, all I might need is some tweaking...

For a pdf-plug-in see the 1.7 source, note that the interface for the plug-in is probably changed, so you will need to do some tweaking. Note however that the closed-source UDS program handles all menu-function, so adding changing/functionality will not be possible when using the plug-in approach.
For the stand-alone pdf-viewer, better wait for Iñigo

Originally Posted by MrWarper

Anyway, another hypothetical question (I haven't had a real look at code yet, this is just some warm up). I really like the UDS interface so in principle I'd prefer to build any new stuff as plugins. Do you think it would be a lot of work to modify the erbrowser and make it into an UDS plug-in?

I think that UDS is not good at handling dynamic content, if I remember well a buffer with the content for a page is requested. UDS decides when to show it and how long to cache is.

Originally Posted by MrWarper

Sure, I always search and read before I ask anything, but it's not always easy to find what you're looking for, so please feel free to tell me to go RTFM anytime -- as long as you tell me where any specific FMs are

Well, the forum is like a maze, it is hard to find anything and if you found it, its is hard to find it back again (when you forgot to make a short-cut, as I normally do ).

As Iñigo already sad, just ask any question, there are several people that are willing to help.