Forth
Stack-based, extensible language used in embedded systems, bootstrapping, and as the base of OpenFirmware.
untyped
compiled
since 1970
stack-basedconcatenativeimperative
Forth is built around a data stack and a return stack — all operations push and pop values. Its self-hosting compiler can be implemented in under 1000 words of machine code, making it popular for bootstrapping systems with minimal resources. OpenFirmware (used in Sun, Apple PowerPC, and OLPC machines) is implemented in Forth, as are many embedded microcontroller environments.