Mobipocket is an excellent format for small reading devices, and it is a format that can be read on the Kindle (if the book is not restricted by digital rights management ); this is not surprising since Mobipocket, originally a French company, is owned by Amazon.com. 

The Mobipocket reader has very nice library presentation in its PC desktop edition.  The small device software does a fine job of handling East Asian character text.

The Mobipocket reader software can be downloaded from:  mobipocket.com

For additional details also see Mobipocket Home (from eBooks.com)