@ywazme_ https://nim-lang.org/docs/mm.html In general: - refc - old default memory management ([garbage collector](https://en.wikipedia.org/wiki/Garbage_collection_(computer_science)) that runs alongside your program), a bit more wasteful on resources than ARC, ever so slightly more stable - ARC - automatic ref counting, (deterministic gc, that is applied at compilation step) you must avoid cycles in your ref objects or it will leak memory `roughly speaking the memory for a variable is freed when it goes "out of scope"` - ORC - new default strategy, essentially it's ARC + cycle collector (O in name stands for cycle), low overhead over ARC, ref cycles don't leak memory none - turns off memory management, use alloc and free (as you would in C), also most of standard library will leak, so write your own functions (as you would in C) or just don't use this option - Boehm and Go - not really supported, better to avoid - Atomic ARC - not sure about status of this one, could be unstable - mark and sweep - no idea about support (does anyone use this?) I would just stick with default ORC, unless you have to use something else and know what and why.