Processor/1

Processor/1 or P/1 is an esoteric RISC architecture.

Architecture
P/1 is a 64-bit architecture where every register is 64-bit wide. General Purpose Registers are available to the programmer, while special registers are altered by system operation.

Implementations
As of 2007, only one software implementation exists of the P/1 architecture exists (a crude virtual machine developed in .Net). There is no hardware implementation yet.

As of 2016, a new software implementation exists (unstable).

XASM: Processor/1 Cross Assembler (requires .Net framework)

XASM: Processor/1 Machine (requires .Net framework)

P/1 implementation in C (With a little assembler written in Python)