These lessons are based on the excellent work done by Tony Parisi at www.learningwebgl.com, which are also based on the NeHe lessons at nehe.gamedev.net. The target audience for these lessons are programmers who want to understand the nitty gritty of the WebGL rendering engine. To do so, you're going to need a modern web browser (Chrome, Firefox, Safari, or IE 11) as well as some tools.
If you're already using dart, then you should have all the tools downloaded. If you're new to dart, head over to www.dartlang.org and download the Dart Editor, which comes with all the tools you'll need, including Dartium - a version of Chromium running the DartVM! If you're used to programming in C-style languages like Java, then you should feel right at home.
I will try to point out interesting features of Dart in the code snippets
The Dart language is continuing to evolve. The source of truth for these lessons should be the code repository on GitHub
The source for these lessons is currently located at github.com/jtmcdole/dart-webgl. You can install free Git tools for every major operating system.