Bicho is a Scheme for those little devices in your life: arduinos and other microcontrollers that have teensy-weensie heaps.
It's early days, but the feature list will probably look like this:
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Native compilation, initially targetting the atmega328p (the chip in arduinos, 2KB SRAM and 32KB flash memory)
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Mark/compact GC (about 12.5% memory overhead, 1 or 2 KB code overhead)
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Flexible stack/heap division: you can recurse as much as your memory allows. If the stack pointer reaches the heap pointer, GC happens to try to compact the heap. Otherwise board will reset.
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13-bit fixnums (-2048 to +2047)
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Vectors, strings, 8-bit chars,
#t/#f/(), symbols, boxes, pairs, closures -
Primitives for peeking and poking I/O registers
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Expanded, optimized, and compiled from Guile Scheme, so you can use powerful macros and procedural abstractions, relying on partial evaluation, contification, closure optimization etc to produce good code
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Implemented in Guile Scheme
Only the GC is done, really. We'll piggy-back on Guile's compiler so mostly what's needed is the backend, the runtime, and a way to link static binaries. Not sure if it's possible to allow a bootloader to be tacked on the front, otherwise these images would need a separate piece of hardware to install on arduino devices.