Nim is cool. Easy to read python-like syntax, strongly typed, compiles (not transpiles) to C, so you can use common C tools like valgrind, gdb, musl, etc.
Small footprint, devel version supports deterministic gc (arc/orc).
One of the greatest interops with C, C++ or JS (C and JS are not mixable, obviously)
I've only used Nim in hobby/toy projects, but it was very pleasant experience.