This gem is called RBT, which is an abbreviation for "Ruby Build Tools". Essentially, this project is a collection of different ruby scripts/classes that may aid in the process of compiling or installing programs from source, but also allow installation from binary, from a remote or from a local location (e. g. a file in a directory on the local harddisc/SSD). There are presently 3798 registered programs available as part of the RBT project. For more information about the project, have a look at the documentation, which can be found at the bottom right side on the homepage of this gem ( or simply visit the following link: https://www.rubydoc.info/gems/rbt/ )