UNIX-like reverse engineering framework and command-line toolset
Capstone disassembly/disassembler framework
Unicorn CPU emulator framework (ARM, AArch64, M68K, Mips, Sparc
Next Scripting Framework (NSF)
The best library to work with .Net Assemblies in any programming lang.
PHP bindings for the cross-platform GUI library wxWidgets.
Universal programmer/debugger. Universal embedded software framework.