Dev.Opera for the Opera web browser. See especially the Advanced documentation for specifications and APIs supported. Much of this just says, “Opera fully supports …”, and refers you to the applicable specification documents.
Chrome/Chromium — I can’t find any detailed application developer documentation (tutorials, reference, etc.); if anybody does, let me know so I can link to it from here. Maybe this is because they aim to follow web standards?
Microsoft does not seem to provide any general tutorials for the canvas. (If you find one, let me know.) Theirs was the last major browser to get into the act, so maybe they figured that programmers already knew how to use the canvas by then.
Internet Explorer versions < 9 do not have native support for the canvas; for them, you can use ExplorerCanvas.
Arista Transcoder is a nice video format conversion tool for Linux/GNOME, easy to use, supporting both GUI and command-line usage.
Online-Convert offers conversion of audio to Ogg [Vorbis], video to WEBM, and other formats, as a web service. I haven’t tried it, so I don’t know how good it is. There’s the obvious penalty of having to upload and download your files.
This course does not have time to go into video and audio editing techniques.
If you’re a Mac or Windows users, you probably know your preferred applications.
For Linux users, I recommend Ardour for serious audio editing.
For years, Linux users had poor choices for video editing. Several programs were available, but were buggy and/or feature-poor. Now, that has changed. OpenShot is a new (since 2008) high-quality video editor. You may also find PiTiVi worthwhile. OpenShot uses the MLT framework; PiTiVi uses GStreamer.
Inkscape is a free, multi-platform, vector graphics drawing program which uses SVG as its native file format. Besides the WYSIWYG editor, it provides an XML tree editor (“Edit” menu / “XML Editor”), so you can pretty directly see how the source code and drawing correlate.
The WebRTC project aims to provide real-time audio/video communication through web browsers, using the new HTML5 getUserMedia API to access the microphone and camera without resorting to Flash or other plugins.