This assumes negatives are represented as two's-complement, but that's implementation-defined. Testing whether a negative number is even by ANDing it with 1 won't work in a system that uses one's-complement.
A handful of ancient legacy systems. Very few people today need to worry about their webapp being ported over to UNIVAC.
Unisys apparently ships some emulators of a old system that still use one's complement... much as I hesitate to ever link to any ESR material, there's a good article here: