Programmable Logic/Tools

Design

 * XILINX Vivado
 * XILINX ISE WebPACK (Discontinued - Legacy software)

Simulation

 * Icarus Verilog (Wikipedia article)
 * ModelSim
 * XILINX ISE WebPACK

Synthesis

 * XILINX ISE WebPACK

Implementation

 * XILINX ISE WebPACK