Capstone disassembly/disassembler framework
Unicorn CPU emulator framework (ARM, AArch64, M68K, Mips, Sparc
Machine graph audio engine for computer games
make a small dumpfile of kdump
C/C++ function instrumentation (AOP, exception/stack tracing, GC)
Positional Audio Communication for Minecraft with Mumble
something that writes code for you