Icarus Verilog is an implementation of the Verilog hardware description language compiler that generates netlists in the desired format (EDIF) and a simulator. It supports the 1995, 2001 and 2005 versions of the standard, portions of SystemVerilog, and some extensions.
Icarus Verilog is available for Linux, FreeBSD, OpenSolaris, AIX, Microsoft Windows, and Mac OS X. Released under the GNU General Public License, Icarus Verilog is free software, an alternative to proprietary software like Cadence's Verilog-XL.
As of release 0.9, Icarus is composed of a Verilog compiler (including a Verilog preprocessor) with support for plug-in backends, and a virtual machine that simulates the design. To view waveforms, a program like GTKWave can be used. [Wikipedia]
Icarus Verilog documentation can be found here.
The Icarus Verilog can be downloaded here.
ICARUS VERILOG
Community
Icarus Verilog
Digital EDA
Free