An open source design system that's fully customizable and agent ready

An open-source C++ library developed and used at Facebook.

A virtual machine for executing programs written in Hack.

Facebook's branch of Apache Thrift, including a new C++ server.

A Scalable, User-Friendly Source Control System.

Sets of libraries and tools to write applications and libraries mixing OCaml and Rust. These libraries will help keeping your types and data structures synchronized, and enable seamless exchange between OCaml and Rust

Rebalancer is a domain-specific language and tool for specifying and solving assignment problems (eg, putting balls in boxes with complex rules).

Lexical is an extensible text editor framework that provides excellent reliability, accessibility and performance.

Meta's BGP (Border Gateway Protocol) routing daemon for large-scale data center networks, built as part of the FBOSS forwarding stack.

Pluggable in-process caching engine to build and scale high performance services