releng-tool can be used to assist in the building of a project. This tool allows a user to define one or more packages to process. Each package has the ability to perform several stages: fetching, extraction, patching, configuration, building and installation. What a package defines will vary for a given project. The simplest type of package is script-based that allows a user to define custom scripts on how to perform various stages. A package is not required to handle every stage. Helper package types are provided (e.g. autotools, CMake, etc.), for projects using common build capabilities.

While this tool can assist in the configuration and building of a project, the framework does not attempt to provide a perfect sandbox for the process. Users defining their projects will have ownership on what compilers/toolchains are used and the interaction between the staging/target area and the host system.