Alliance/Coriolis Toolkit & Checker contain various design flow examples, blocks or full chips. It is also used as a regression test for all the tools.

Coriolis VLSI CAD Tools

Alliance VLSI EDA. A complete set of GPL tools to design an ASIC.

The BoolEAN POLynomial Evaluation library

FYFY (FamilY For unitY) is an Entity Component System framework (ECS) specially made for Unity.