Slashdot tells that there is a way to have a local copy of Wikipedia on your computer:
Want your own copy of English Wikipedia with images? Got 100 GB of disk space? Then open-source app XOWA may be of interest to you. The project released torrents yesterday for the 2013-11-04 version of English Wikipedia. There’s 100 GB of sqlite databases containing 13.9 million pages, and 3.7 million images — readable from any Windows, Linux, or Mac OS X system.
It is, of course, a frozen in time version of Wikipedia – without any further updates or edits, but it might be quite handy for those places where Internet is not common or stable. Another use for this would be as a source of data for parsing tools or linguistic analysis, etc – working with local copy is much faster than fetching it page by page from the online.