Icarus Verilog is a work in progress, and since the language standard is not standing still either, it probably always will be. That is as it should be. However, I will make stable releases from time to time, and will endeavor to not retract any features that appear in these stable releases. The quick links above will show the current stable release.
The main porting target is Linux, although it works well on many similar operating systems. Various people have contributed precompiled binaries of stable releases for a variety of targets. These releases are ported by volunteers, so what binaries are available depends on who takes the time to do the packaging. Icarus Verilog has been ported to That Other Operating System, as a command line tool, and there are installers for users without compilers. You can compile it entirely with free tools, too, although there are precompiled binaries of stable releases.
