Chameleon is a polymorphic engine for x86_64 position independent shellcode that has been created out of the need to evade signature-based detections in red team environments.

A metamorphic binary transformation engine based on r2pipe and radare2.

metamorphic engine in python

A python metamorphic engine for PE/PE+ files.

Automatic Metamorphic Testing of Machine Translation Software

A metamorphic shellcode obfuscator capable of generating more unique shellcodes than there are atoms in the OBSERVABLE UNIVERSE and designed for shellcodes/implants that need to run in W^X memory.