ModelSim PE Student Edition is a free download of the industry leading ModelSim HDL simulator for use by students in their academic coursework. The ModelSim-Altera Edition software is licensed to support designs written in 100 percent VHDL and 100 percent Verilog language and does not support designs that are written in a combination of VHDL and Verilog language, also known as mixed HDL. The Mentor Graphics ModelSim is a powerful simulator and debugging environment designed by a world leader software company in electronic hardware and software design solutions for VHDL, Verilog and SystemC.