Zen is popular set of user layouts and configs to increase productivity in MODO. It was originally developed by Mechanical Color LLC as a proprietary paid product, and is now released as open-source under the MIT license.
MODO layout configs are notoriously corruptable. Installing Zen for the first time requires that you reset your MODO preferences, and uninstalling it will also require a preferences reset. The mc_lifesaver kit is strongly recommended, as it will help to minimize the pain inherent to this process.