I was looking for a freeware reference software for a client and I came across Wikipedia Selection for Schools. This is the offline version of the popular online encyclopedia. It contains topics suited for school use well curated by volunteers of the SOS Children charity group.
The 2008/9 edition contains about 5500 topics that include Arts, History, Information Technology, Math, Science, etc. It’s about the size of a twenty-volume encyclopedia that includes 34,000 images and 20 million words.
The Wikipedia Selection for Schools may be downloaded via a torrent client. Download its torrent from the SOS Children website. After downloading, extract the file and open the “index.html” file using a web browser.