* [**Python**: *Building a basic HTTP Server from scratch in Python*](http://joaoventura.net/blog/2017/python-webserver/)
* [**Ruby**: *Building a simple websockets server from scratch in Ruby*](http://blog.honeybadger.io/building-a-simple-websockets-server-from-scratch-in-ruby/)
#### Build your own `CI Server`
* [**Ruby**: *Writing a CI Server*](https://developer.github.com/v3/guides/building-a-ci-server/)
* [**C**: *Building a software and hardware stack for a simple computer from scratch*](https://www.youtube.com/watch?v=ZjwvMcP3Nf0&list=PLU94OURih-CiP4WxKSMt3UcwMSDM3aTtX) [video]