Gyo is a single-cycle Forth virtual machine.
This virtual machine was created as a result of experimenting with stack-effect checking and so was designed around the idea that each opcode is encoded with its own stack effect. The layout of the opcodes is inspired by Koopman's Stack Computer: The New Wave.
More details shortly.
The programming of this computer is akin to writing Forth programs. At the assembly level, opcodes are made from various mnemonics:
14R10— Gyo Release