ModelSim Alternatives

The gEDA project has produced and continues working on a full GPL'd suite and toolkit of Electronic Design Automation tools. These tools are used for electrical circuit design, schematic capture, simulation, prototyping, and production.

Sketch, simulate, and share your circuits, entirely in your browser -- no install required. Easy schematic capture and powerful SPICE-like, mixed-mode circuit simulation helps EE students, electronics hobbyists, and electrical engineers design faster.

Automated schematic generation application.

System Verilog, Verilog, VHDL, SystemC HDL Simulator for ASIC Design and Verification

Educational virtual 3D laboratory simulator helps students, teachers, and tutors conduct electrical circuit experiments by providing realistic equipment access anywhere, avoiding availability issues and safety hazards, and enhancing learning with immediate feedback and...

Spice based electronic circuit simulation and circuit analysis software. 5Spice has the analysis capabilities needed by experienced circuit designers while remaining easy to use.

Provides products and services that accelerate innovation in the global electronics market.

System Verilog, Verilog. VHDL, SystemC, HDL simulator targeting ASIC and large FPGA designs. (Wrongfully supports crappy OVM and UVM legacy trash libraries and hardware de-accelerators).