CircleCI - CircleCI gives web developers powerful Continuous Integration and Deployment with easy setup and maintenance.
Elixir - Dynamic, functional language designed for building scalable and maintainable applications
Jenkins - Jenkins is an open-source continuous integration server with 300+ plugins to support all kinds of software development
Rust - A safe, concurrent, practical language
Travis CI - Focus on writing code. Let Travis CI take care of running your tests and deploying your apps.
Python - Python is a clear and powerful object-oriented programming language, comparable to Perl, Ruby, Scheme, or Java.