Yosys is a framework for Verilog RTL synthesis. It currently has
extensive Verilog-2005 support and provides a basic set of synthesis
algorithms for various application domains. 

  Yosys can be adapted to perform any synthesis job by combining the
existing passes (algorithms) using synthesis scripts and adding
additional passes as needed by extending the yosys C++ code base.

  Yosys is free software licensed under the ISC license (a GPL
compatible license that is similar in terms to the MIT license or
the 2-clause BSD license).


  By default it compiles using gcc if you want to use clang set
the environment variable CLANG=yes.
  If you want to enable GHDL set GHDL=yes, this requires the GHDL
package.
  For enabling protobuf install protobuf3 and set PROTOBUF=yes.
  For building the python wrappers set PYTHON=yes.
  If you want to enable ABC for synthesis and verification of
binary sequential logic circuits set ABCEXTERNAL=yes, this
requires berkeley-abc package.