Icarus Verilog is a Verilog simulation and synthesis tool. It operates as a compiler, compiling source code written in Verilog （IEEE-1364） into some target format. For batch simulation, the compiler can generate an intermediate form called vvp assembly. This intermediate form is executed by the ``vvp'' command. For synthesis, the compiler generates netlists in the desired format.
GTKWave is a fully featured GTK+ v1.2 based wave viewer for Unix and Win32 which reads LXT files as well as standard Verilog VCD/EVCD files and allows their viewing. You can grab version 1.3.11 here .
If you have difficulty in downloading the GTKWave tarball properly, get it from here and rename the file so it doesn't have the ".bin" extension.
The Win32 version is now available （and has been for quite some time） on The Win32 GTKWave Homepage , thanks to Udi Finkelstein . A ready-to-run all libraries included Pentium-Pro optimized version of the binary may be found locally here. Ports to other platforms which GTK supports should be trivial.
gtkwave是一个基于GTK+波形查看器，可以支持LXT, LXT2, VZT, GHW文件以及标准Verilog VCD/EVC文件。
iverilog: no source files.
Usage: iverilog [-ESvV] [-B base] [-c cmdfile|-f cmdfile]
[-D macro[=defn]] [-I includedir] [-M depfile] [-m module]
[-N file] [-o filename] [-p flag=value]
[-s topmodule] [-t target] [-T min|typ|max]
[-W class] [-y dir] [-Y suf] source_file（s）
See the man page for details.
>iverilog -o hello hello.v