This is the RicMonk: a 3-link brachiating robot that uses passive grippers for more efficient operation. This robot resembles gibbons anatomically. This is an open source project that uses low cost components. It can perform bidirectional brachiating maneuvers.
This robot uses has 2 x Quasi-Direct-Drives that allow for agile movement. The above video shows this robot in action.
[where to find it] [credit: Shivesh Kumar, Mahdi Javadi, Shourie S. Grama, Hossein Zamani Boroujeni]