EBook "standard" from IDPF
It's basically a zipped archive that includes XHTML, CSS, image files, and Meta Data.
- if you want to play with one, just
- make a copy of the '.epub' file
- change the extension of the copy to '.gz'
- use your unzipping-tool of choice - you'll get a directory with all the asset files inside.
For my main reading on my Android Tablet I use MoonReader. On my phone and laptop I use FBReader.
GoogleDocs has a download-as-epub feature! For simple informational docs, that's handy.
Sigil is an Open Source WYSIWYG editor http://code.google.com/p/sigil/
CaLibre generates EPub or Mobi from PDF, RTF, HTML, OpenOffice ODT, etc.
E Cab is free (but not Open Source), generating from HTML or PlainText.
from TEI or DocBook XML
Daisy Pipeline is an Open Source set of tools, but sounds a bit complicated
Help And Manual has an Export feature
Sept'2013: writing/editing in Libre Office then converting with Writer2e Pub plugin.
Jan'2011: Paul Biba summarizes workshop by Joshua Talent.
Info on raw format