FPGAsm
Create fast bare-metal FPGA designs without Verilog or VHDL
FPGAsm is a low-level alternative to verilog and VHDL. A near-instant 'assembler for FPGAs', this simple yet powerful language facilitates bottom-up design, layout and wiring of modules, and generation of .xdl output.
With about 10 keywords to learn, you can start making circuits in minutes. Now you can focus on learning the ins and outs of the FPGA instead of complex tools and languages.
Fast turnaround time and bottom-up approach invite exploration, experimentation, live circuit...