Master Ruby.

A shell is a command-line interface that executes commands and manages processes. In this challenge, you'll build your own POSIX compliant shell that's capable of interpreting shell commands, running external programs and builtin commands like cd, pwd, echo and more.

Along the way, you'll learn about shell command parsing, REPLs, builtin commands, and more.

HTTP is the protocol that powers the web. In this challenge, you'll build a HTTP server that's capable of handling simple GET/POST requests, serving files and handling multiple concurrent connections.

Along the way, we'll learn about TCP connections, HTTP headers, HTTP verbs, handling multiple connections and more.

Discover concurrent programming in Ruby while also learning about TCP servers, network programming, and the Redis Protocol.

Learn about .torrent files and the famous BitTorrent protocol. Implement your own BitTorrent client in Ruby.

Dive into the internals of Git. Discover how Git stores and moves around data, its transfer protocols, and more. A unique exercise in making network requests with Ruby.

Learn about B-Trees, the foundation of every relational database. Explore Ruby's API for reading/writing files, and handling custom file formats.

DNS is a protocol used to resolve domain names to IP addresses. In this challenge, you'll build a DNS server that's capable of responding to basic DNS queries.

Along the way you'll learn about the DNS protocol, DNS packet format, DNS record types, UDP servers and more.