Kiwix

Kiwix reads ZIM archives — compressed snapshots of websites that keep the text, the images and the internal links of the original — and presents them as ordinary web pages with no network connection involved. Wikipedia editions are the most familiar archives, but the same format carries Wiktionary, Project Gutenberg, Stack Exchange sites and medical reference collections.

The desktop application includes a catalogue of archives that can be downloaded from inside the program. Entries are split by language and by how much media they include, so a text-only copy can be chosen where bandwidth or disk space is short. Once a file is on disk, Kiwix indexes it for full-text search and renders articles in an embedded browser view.

The intended setting is places where connectivity is intermittent, expensive or filtered: schools with no reliable line, ships, clinics, field work. Storage is the main constraint. An illustrated archive is far larger than a text-only one, and the whole file has to be downloaded before anything in it can be read.