Hydra is a Nix-based continuous build system, released under the terms of the GNU GPLv3 or (at your option) any later version. It continuously checks out sources of software projects from version management systems to build, test and release them. The build tasks are described using Nix expressions. This allows a Hydra build task to specify all the dependencies needed to build or test a project. It supports a number of operating systems, such as various GNU/Linux flavours, Mac OS X, and Windows.
At Delft University of Technology we run a Hydra-based build farm to build and test the NixOS GNU/Linux distribution, the Nix Packages collection, the Stratego/XT program transformation system, and various other open source projects. If you want to use our build farm for your open source project, please let us know.
Hydra has a work-in-progress manual. There also is an ancient, totally outdated paper about Hydra.
If you would like to give some feedback, or report some bugs, please visit: