The offline version uses Kiwix, open-source software that allows Web content to be read offline. There are versions of offline Wikipedia for Windows, Linux and Mac.
Because the offline reader can handle only so much data, Wikimedia is developing content libraries that are made up of selected material from the broader Wikipedia collection that is available online. The general English version (version 0.8) contains some 47,300 articles taken from all subject areas. Volunteer editors selected them based on their importance and quality.
If you’re interested in learning more about this beta version of offline Wikipedia, read all about it at the Offline Projects wiki.