Open-source vector similarity search for Postgres

libSQL is a fork of SQLite that is both Open Source, and Open Contributions.

Pure Data as a plugin, with a new GUI

DFA regular expression library & friends

Core Lucy compiler

Statechart library and editor

A math-aware search engine.

State machine framework for reactive embedded systems

Serverless Actor Model Framework

A framework for implementing hierarchical finite state machines (HSMs) in C code. It's a good fit for firmware projects, and helps keep your event-driven system orderly with readable code.