This is a small JavaScript utility library for checking if a number is ±0 (positive or negative zero). It provides three functions: `isZero` to check if a number is ±0, `isPositiveZero` to check if it's +0, and `isNegativeZero` to check if it's -0. The library is useful for developers working with JavaScript who need to distinguish between positive and negative zero, which can be important in certain mathematical operations.