GTKWave is a fully featured GTK+ based wave viewer for Unix, Win32, and Mac OSX which reads LXT, LXT2, VZT, FST, and GHW files as well as standard Verilog VCD/EVCD files and allows their viewing. You can grab version 3.3.89 here. Documentation in pdf format can be found here.
Native Win32 and OSX binaries are available here,
however if you are a Windows user running Cygwin, running under that is recommended instead.
A Mac port can be found both here and here.
Ports to other platforms which GTK supports should be trivial.