Qiskit is an open-source SDK for working with quantum computers
Indexing and query tools for very large text corpora
Automated detection of the unknown early map projection
Open hardware SPM controller with advanced sampling support.
A simulation program for thyroid homeostasis.
PDP-OmniSim simulating parallel and distributed processing systems
Lisflood batch processor
An Open Source POWERLINK Stack
Arduino core for ATtiny 1634, 828, x313, x4, x41, x5, x61, x7 and x8
AVR simulator IDE
An open source VR headset with SteamVR supports for $200
MIDI for Arduino
Natural Language Processing (NLP) for the Masses
FFT co-processor in Verilog based on the KISS FFT
Summary
Calculation of Primenumbers
Powerfull pre-processor
A Development Framework for Coldfire
mathSuite Speed & Matrix Stream Processor
Open implementation of the x86 architecture