Miasm is a free and open source (GPLv2) reverse engineering framework. Miasm aims at analyzing/modifying/generating binary programs. It embeds its own disassembler, intermediate language and instruction semantic. It uses libtcc to jit C code generate from intermediate representation. It can emulate shellcodes, parts of binaries. Python callback can be executed to emulate library functions. It is written in Python and written in the language of assembly and disassemblers.
Source: https://thehackernews.com/2011/07/smiasm-reverse-engineering-framework.html