Snowy background with canvas dsone

Wintertime, usually that time of year when snow is appearing on websites here and there.

Many of them use the terrible jQuery.animate(), performance-wise a catastrophical choice.
A particularly used solution was so terrible in IE, it breaks the entire display of the website, hogs 100% GPU, spikes at roughly 75% CPU and includes occasional flickering of the website. Firefox is a bit laggy, Chrome no issues.
Sadly, IE still has to be supported on many coporate websites and this snowy theme is always an issue.

Curiously, IE has no issues with canvas rendering, though.
So, how about a reusable snow effect for canvas?

This JavaScript snippet is based on this Codepen.

  Creative Commons License
Algorithm Animation Snow IE Canvas