Metasm is a cross-architecture assembler, disassembler, compiler, linker and debugger.
It has some advanced features such as live process manipulation, GCC/Microsoft Visual Studio-compatible preprocessor, automatic backtracking in the disassembler (similar to "slicing"), C headers shrinking, linux/windows/remote debugging API interface, a C compiler/decompiler, a gdb-server compatible debugger, and various advanced features. It is written in pure Ruby, with no dependency.
Blinged JSON Validator is a free app to validate JSON files with syntax highlighting, whitespace indentation, error messaging, and hotkeys.
