FREE VHDL SIMULATORS

Simulator	Comment	Download from	Windows	Linux	Mac OSX
Aldec Active-HDL, Student Edition	Students only	Aldec Download page	Yes	No	No
ModelSim Altera Starter Edition	Only Altera FPGAs	Altera Quartus Web Edition	Yes	Yes	No
ISim	Only Xilinx FPGAs	Xilinx Webpack	Yes	Yes	No
Simili		SymphonyEDA website	Yes	Yes	No
GHDL	limited features; only VHDL-93	GHDL website	Yes	Yes	Yes

We have not had great results with FreeHDL or with Green Mountain VHDL. It seems that these projects may have been terminated.
GHDL on Mac OSX uses Wine, but works without problems.