Icarus Verilog?

Question

What is Verilog Icarus?

Answer 1

Icarus is a free Cross-platform simulation & synthesis tool for Verilog.

Answer 2

Icarus Verilog is the free Verilog simulator released under the GNU General Public License. The icarus team declare that it is also a synthesis tool. I didn't work with it so I haven't an opinion about such it's declared possibility. It supports Verilog standards up to 2005 and partially supports SytemVerilog.