Jim - An overview of Jim capabilities
RANDOM.ORG - RANDOM.ORG offers true random numbers to anyone on the Internet.
Insect - High precision scientific calculator with full support for physical units.
GeneratorMix - A place with hundreds of generators split into different categories from science to entertainment.
errProof - The website has a lot of useful and unique tools.
Random Number Generator - Randomly generate integers or floating point numbers within a given range and specified discrete or continuous statistical probability distribution.