The starter Worlds are the best Worlds to use to get started with Authoring. These are all plain text. You can view their JS. Clone them and edit their JS to get started.
The following starter Worlds use the normal starter API: Three r80. This has Three.js graphics support and built-in mouse (and touch) camera control. This API is Three.js release 80. Some of these Worlds use a Mind. Some do not. Click World image to run the World.
The following are starter Worlds for a more advanced API: Three r80 with Physics. This uses Three.js with mouse (and touch) camera support and built-in physics support from the Physijs library. Click World image to run the World.
The following are starter Worlds for an absolute minimal API: Canvas. This does not use Three.js or any graphical library. It just has a canvas, on which World authors do their own 2D or WebGL rendering. This can make for a more complex World, but is needed for some authors. (Three.js or other libraries would only get in their way.) Click World image to run the World.