jQuery Migrate is the more common of the two in our index: it runs on 6,902 websites against 14 for SimplexNoise.js, and 11 sites use both. Counts come from real scans, not vendor claims.
Query Migrate is a javascript library that allows you to preserve the compatibility of your jQuery code developed for versions of jQuery older than 1.9.
SimplexNoise.js is a library that generates pseudorandom noise functions, designed for use in video games, graphical applications, and demoscene production.
11 sites run both jQuery Migrate and SimplexNoise.js. That is 79% of the sites using SimplexNoise.js, the smaller of the two.
Want to know which one a particular site uses? Look it up and see its whole stack, or compare two sites side by side.