Top 5 open source version control tools are CVS, SVN, GIT, Mercurial and Bazaar. They provides great way to enable collaboration, maintain versions and track changes.
What Is Source Control?, Source Code Management
Top 12 open source sysadmin tools in 2020 (As per experts)
5 Great Project Management Tools for System Admins
Top 5 Open Source Code Editors
Version Control Systems - GeeksforGeeks
What is The Role Of the System Administrator? - nixCraft
What is DevOps? — Tech at GSA
How and Where to Learn Coding For Free?
The Qualities That Make a System Admin an Asset for an Enterprise
20 Top Windows SysAdmin Tools You Should Know