GitLab is a web-based DevOps lifecycle tool that provides a Git-repository manager providing wiki, issue-tracking and continuous integration/continuous deployment pipeline features, using an open-source license, developed by GitLab Inc. The software was created by Ukrainians Dmitriy Zaporozhets and Valery Sizov.
The code was originally written in Ruby, with some parts later rewritten in Go, initially as a source code management solution to collaborate with his team on software development. It later evolved to an integrated solution covering the software development life cycle, and then to the whole DevOps life cycle. The current technology stack includes Go, Ruby on Rails and Vue.js.
It follows an open-core development model where the core functionality is released under an open-source (MIT) license while the additional functionality is under a proprietary license.
~ Wikipedia 2020