Tooling Resources

Test Benching
Icuras verilog: Iverilog (Install Guide)

Free and opensource tooling for Verilog and Systemverilog.

Modelsim: {Comes with Quartus, Vivado, and Libero}

FPGA Software
For Altera FPGAs
Quartus Prime: Quartus Download Page

*NOTE: To download Quartus Prime Lite Editition, you need an Intel.com account. I personally am using Lite v20.1

For Xilinx FPGAs
Vivado: Vivado Download Page

*NOTE: To download Vivado, you need a xilinx.com account. I personally have very little Vivado experience.

For MicroSemi FPGAs
LiberoSoC v12.0+: LiberoSoC Download Page

*NOTE: To download Libero, you need a Microsemi.com account. I personally have very little Libero SoC experience.

LiberoSoC v11.9-:LiberoSoC Download Page

*NOTE: To download Libero, you need a Microsemi.com account. I personally have very little Libero SoC experience.

Graphical Circuit Design:

Logisim Evolution: Logisim Evolution Download Page

Amazing tool for schematic style circuit design. It can output directly to VHDL and compile it for an FPGA.... although its very buggy and requires some manual editing of the project it generates before you can actually flash the design to a board. I have used Logisim Evolution for years.

Digital: Digital Homepage

I have heard great things, it can export to HDLs and can even support parameterization to an extent. I personally have very little Digital Experience.