FreeSWITCH supports many scripting languages, both from the dialplan and command line. For each language, a specific FreeSWITCH module implements the dialplan and command line interface.
The best thing is that support for all of them comes from the same source code base: we use the Simplified Wrapper and Interface Generator (SWIG, http://www.swig.org/) to make the core FreeSWITCH library accessible to scripting.
The main advantage of using SWIG is that, in each resulting scripting language, the FreeSWITCH objects, methods, and functions all look the same, with the same arguments and return values. In fact, all the scripting languages access the same APIs from the FreeSWITCH core library (the same library used by the FreeSWITCH executable itself). SWIG ensures that this library interfacing is done in the same way for all scripting languages, instead of duplicating efforts, avoiding confusing different ways to call into the APIs.
So, there is basically only one documentation...