Fluxbox is a minimalistic windowmanager for X.
Fluxbox is a windowmanager for X that started in 2001 as a fork of the Blackbox 0.61.1 code, but with significan enhancements and continuing development. It is very light on resources and easy to handle but yet full of features to make an easy, and extremely fast, desktop experience. It is built using C++ and licensed under the MIT-License.
Configuration of Fluxbox is not normally done with gui tools, rather by the editing of several text files contained within ~/.fluxbox. Some useful sites that deal with this configuration are:
Fluxbox is not just for those with minimalist computer hardware, it is also for those with powerful computers and no patience with the heavy hardware requirements of some modern Linux Desktop Environments.