Fastwiki!

Kiwix enables you to have the whole Wikipedia at hand wherever you go! On a boat, in the middle of nowhere or in Jail, Kiwix gives you access to the whole human knowledge. You don't need Internet, everything is stored on your computer, USB flash drive or DVD!

MyTetra is open source and cross platform personal manager for information accumulation. It is powerful program for data memorization and structuring notes.

The free, open-source, offline wiki application

WikiTaxi It's a portable application that delivers the Wikipedia of your choice to wherever you go. WikiTaxi enables you to read, search, and browse Wikipedia offline. No Internet connection is needed, all pages are stored in a WikiTaxi database. Because Wikipedia is constantly growing, WikiTaxi uses compression to make sure that the database stays reasonably small. The huge English Wikipedia easily fits on a 8 GB memory stick.

Wikipedia, better than ever—on iPhone, iPad, and Apple Watch. Discover the world and enjoy beautiful typography with this sleek app.

Evopedia is an offline Wikipedia viewer.

Okawix lets you download the whole content of Wikipedia, with or without images, so that you can browse it offline:Okawix is available in 253 languages and includes sister projects of the Wikimedia Foundation (Wikisource, Wiktionary, Wikiquote, Wikibooks).

Wikipedia is probably the single largest, most comprehensive and simply best information resource out there on the Internet - a really great resource.many people though would like to have access to this giant resource when they're not plugged into the Internet.

Wiki2Touch - A Wikipedia offline reader for the Apple iPhone or iPod Touch