Lisp MCU

http://www.mail-archive.com/picolisp@software-lab.de/msg04823.html

PilMCU is an implementation of 64-bit PicoLisp directly in hardware. A truly minimalistic system. PicoLisp is both the machine language and the operating system:
* Memory management is trivial, just the Lisp heap and the stack
* The built-in database is extended to hold a "file system"
* One SSD per database file for mass storage
* "Processes" run as tasks and coroutines
* Events (timing and interrupts) via a 'wait' instruction
* Complex I/O protocols are delegated to peripheral chips

>>7
For one thing, all variables are dynamically scoped. And they are maintained in a linked list. Every time you refer to a variable, a linear search down the linked list resolves the variable. This all happens at run time. If I also remember right you can't refer to an output stream with a variable. There's an invisible current output stream variable that you can redirect dynamically or something. It's been a long time since I've looked at it.