Setting up a Development Environment
Depending on what you want to build, your requirements for a development environment may be slightly different.
Here we will describe the more or less standard approach to a development environment where a single MODX installation is used to develop one or more extras. When building sites or more complicated applications, it is totally acceptable to do it differently.
This documentation needs to be (re)written as the previous version was not useful. The Building an Extra in MODX Revolution is a good start, explaining the different concepts in tutorial form.