Noodle is a tool for Maya that aims to automatically create overlapping animation for you.
The goal of Noodle is to work in as many situations as possible, with the least amount of work from the user.
While there are many tools out there that may do something similar, Noodle aims to be as simple as possible, whilst still being robust and dependable. Many tools out there claim to work well without physics, but Noodle purposefully utilizes Maya's physics system in order to achieve the best all-round results.
Noodle is also actively being developed and will continue to get better with each version.