There's so pretty much seemingly unique proprietary software. A while ago I found this awesome logic minimizer called "logic Friday". [1] I don't think there's a free or open source version of a tool like this.

I have an idea that the "espresso" algorithm could be used to minimize not only electronic circuits but general boolean expressions for any programming language... I think it would do for a useful refactoring tool.

1: https://web.archive.org/web/20131022051516/http://www.sontra...

It simulates logic, supports automated testing, simulates and analyses combinatorial and sequential logic, comes with a large library of components (generic stuff, specific 7400 logic, displays and memories, etc), it can output VHDL or Verilog, and it can export JEDEC files for GALs.