Geoff, I can tell you what OpenInkPot (OI) does for me on my EZ Reader (& all those in the Hanlin V3 family) and to some extend what it does not do.
It allows me to;
- read several unDRMed formats. e.g. .PRC (& MOBI), RTF, HTML, FB2, TXT, PDF(not any better than others with PDFs)
- use either of two reader SWs, FBreader and Cool Reader (each has unique features, e.g. CoolReader allows the 10 page advance similar to the original Sony)
- search for text string
- delete books from the reader
- change the font to any True Type Font (but not Open Type Font)
- change the font size
- use folders & sub-folders
- standard things like bookmarks, navigation, etc.
What it does not do;
- read DRMed ebooks
- read Epub (yet) (edited 3-4-09 - it does read Epub)
There are two ways to load OI, 1) you can flash it to the internal memory just like updating your firmware or 2) load it on an SD card and keep your original firmware but still change to OI. To chang back to the original firmware, you have to reboot. This second way is ideal to try OI without losing your original firmware.
With the number buttons on the Hanlin V3s it is easy to use. I'm not sure how well it would work on a Sony or Cybook without those keys.
Hopw this helps some.