Jira - The #1 software development tool used by agile teams. Jira Software is built for every member of your software team to plan, track, and release great software.
Python - Python is a clear and powerful object-oriented programming language, comparable to Perl, Ruby, Scheme, or Java.
Redmine - Flexible project management web application
Java - A concurrent, class-based, object-oriented, language specifically designed to have as few implementation dependencies as possible
Mantis Bug Tracker - Mantis Bug Tracker is a free and open source, web-based bug tracking system.
Rust - A safe, concurrent, practical language