MathJax v3 is now in beta release; see the beta branch for details. See the https://github.com/mathjax/mj3-demos for examples and webpacked files for the beta release.
The master branch is not the beta release. It is the current development copy, set up for development testing, as described below.
There are two bootstrap files for running the code:
load.jsfor running in node (node load), andload.htmlfor running in a browser.
These allow you to specify a test file to run. For example,
node load samples/filename.js
will run the file samples/filename.js, while entering
load.html?samples/filename.js
in your browser will run the same file in your browser. If you leave off the file to load, then it defaults to main.js.
Additional arguments get passed to the script in the process.argv array. For example
node load samples/tex2html.js 'x+1'
or
load.html?samples/tex2html.js&x+1
would load tex2html.js passing it x+1 in process.argv[3].
Both load.js and load.html use System.js to manage the loading of version 3 files. In some browsers (e.g., Firefox), you get syntax errors for the files as they load, but that seems to be some side-effect of how System.js works. The code is OK and runs properly anyway.
There is a tiny document in the docs directory that gives the basic structures and some sample code, but it is woefully inadequate at the moment, and may be out of date. More to come later.