LCG is a one of the simpliest algorithms for producing a sequence of pseudo-random numbers. Each next number is calculated based on the previous one and also on three constant parameters that do not change across the numbers sequence, i.e:
sn = (sn-1 * a + c) mod m
That is, with fixed values for a, c and m, each exact sn-1 is followed by the corresponding sn, which obviously restricts LCG algorithm from being used in any security sensitive areas.
As this script is written in Javascript (calculations in pure JS, with jQuery used for UI interaction), it does not rely on any server-side software and may be easily copied and distributed. Feel free to do so. Note that code uses generator function, so it requires ECMAScript 6 support (Chrome or Firefox should fit this).