If you want resources offline to learn about programming and web technologies MDN is for you! and I recommend to use MDN over w3school because w3school is outdated.
Download it offline (2.1gb) at https://mdn-downloads.s3-us-west-2.amazonaws.com/developer.mozilla.org.tar.gz
Use a documentation browsing app like Dash (macOS) https://kapeli.com/dash, Velocity (Windows) http://velocity.silverlakesoftware.com/ or Zeal (Linux) http://zealdocs.org/ instead. These apps will help you get the most out of the docs, by providing a search index and quick access to everything you need.
don't mirror with wget & co, this is putting un-needed pressure on the website and hinders other users. At least make sure https://developer.mozilla.org/robots.txt (which asks for gentle throttling) is properly handled. Wget does not handle this for instance (http://savannah.gnu.org/bugs/?30999).
source : https://kapeli.com/mdn_offline
- CSS.tgz : https://london.kapeli.com/feeds/zzz/mdn/CSS.tgz updated 2 March 2019
- HTML.tgz : https://london.kapeli.com/feeds/zzz/mdn/HTML.tgz updated 2 March 2019
- JavaScript.tgz : https://london.kapeli.com/feeds/zzz/mdn/JavaScript.tgz updated 2 March 2019 Note: Includes DOM docs
- SVG.tgz : https://london.kapeli.com/feeds/zzz/mdn/SVG.tgz updated 2 March 2019
- XSLT.tgz : https://london.kapeli.com/feeds/zzz/mdn/XSLT.tgz updated 2 March 2019
These archives will be updated once every month (or so). Please contact me if anything is wrong.
DevDocs combines multiple developer documentations in a clean and organized web UI with instant search, offline support, mobile version, dark theme, keyboard shortcuts, and more.
DevDocs was created by Thibaut Courouble and is operated by freeCodeCamp. The JavaScript docs along with most of MDN's web reference pages are available on DevDocs. The app is open source and can be run offline: https://github.com/freecodecamp/devdocs It's easy to set up and doesn't require scraping MDN.