I'm a big fan of libtom. The relevant GNU project is gmp: https://gmplib.org/ https://gmplib.org/ In comparison, libtom is very liberally licensed, which is a

I'm a big fan of libtom. The relevant GNU project is gmp: https://gmplib.org/ https://gmplib.org/ In comparison, libtom is very liberally licensed, which is a feature that I think is good to have in a component as low-level component as big math.