Rig Studio is a python script for Maya. This tool help rigger to make any types of rigs.
Modules is a core and philosophy of this rigging system. They can be easy add to rig and connect in any combination. Modules is not only arm, foot, tail, etc.. but many variations of them. For example you can choose needed module of foot for your character.
In RS, module is not simple script, in the main, module is a simple maya scene. It means, user can easy edit it, but better make your own. Create new module from simple template or duplicate existing module and edit it.
Also, you can get additional advanced modules, which will be available soon. One of main missions is make modules for every task. Right now you can use internal RS modules for building rig of humanoid, quadruped or similar characters.
Another main feature of the tool is a using realtime adjustments. After building rig, you can easy correct all joints plament. That give ability match builded rig to any similar character. Without RS, without rebuilding, in realtime even in animation you can correct rig proportions.
RS everywhere use a templates. Modules and even full rigs can be saved as template, and later created by one button.
After building the rig, you can use it in any computer without any plugins.
On highend3d available free dremoRig (human rig) for testing what Rig Studio does. But it only a one of many variations of rigs, that the system can build.
Your thoughts and wishes are welcome. This tool was in development many years, and is not going to stop as exist ideas for fast and easy rigs building.