“Mercurial: The Definitive Guide”, by Bryan O'Sullivan, is a freely licensed book about the Mercurial revision control system.
Home page: http://hgbook.red-bean.com/
The [http://hgbook.red-bean.com/read/ HTML version] is split into one web page per chapter.
The [http://hg.serpentine.com/mercurial/book source code] is available to the adventurous.
Translations
[http://devnull.li/libromercurial/index.es.html Spanish] ([http://mercurial.intuxication.org/hg/mercurial_book_es/ source])
[http://bitbucket.org/rpelisse/hgbook-fr/ French] (Work in progress...)
1. Chinese Translations
[http://bitbucket.org/dongsheng/hgbook/ Source code] (Work in progress...)
The [http://code.google.com/p/i18n-zh/downloads/list?q=label:hgbook HTML/PDF/eBook] (Chinese & English) version is available.
See also: [:BuildingMercurialBook]