Reblogged by cstanhope@social.coop ("Your friendly 'net denizen"):
Spade now has a playground at https://play.spade-lang.org/
It runs the Spade compiler, and simulates the resulting Verilog code along with a VGA monitor right in the browser through web assembly.
Since it simulates an actual VGA/HDMI monitor, the code written here can be uploaded to an #fpga and will behave exactly the same!