youtube_dl is a command-line program to download videos from YouTube.com and a few more sites which some indie sites use to export their content from YouTube. It is released to the public domain, which means you can modify it, redistribute it or use it however you like.
- IndieWeb friendly service Huffduffer has a bookmarklet that posts audio to one's account. Ryan Barrett created http://huffduff-video.snarfed.org/ using youtube_dl to extract audio from YouTube videos to send to Huffduffer from which one can also download and save to one's website.
- David Shanske has used how it looks at video pages for improving the Parse This tool/plugin which is used in several places including for Post Kinds Plugin for WordPress
- Add yourself here… (see this for more details)