I use many self-made libraries for many of my OpenSCAD projects. If you compile one of my scads and it says "file not found", good odds it's looking for one of these.
Also found here are explanations for math too complicated to elegantly display in a computer language, and references I don't want to lose.
Name Last modified Size DescriptionApache Server at burningsmell.org Port 80
Parent Directory - util.scad 2017-09-12 19:53 8.8K Tons of little time-saving one-shots. Latest version. util-0.0.1.scad 2017-01-09 19:28 6.2K Old lib for pre-2016 OpenSCAD util-0.1.1.scad 2017-09-12 19:53 8.8K Now with support() module dimensions/ 2021-03-15 18:48 - Measurements and Tables Gerotor_Modeling_with_NX3.pdf 2017-01-09 22:15 1.2M Magic formula for making gerotors tsmthread2.scad 2019-01-20 00:05 12K Faster and better thread gen tsmthread.scad 2017-01-09 22:11 2.3K Fast OpenSCAD Thread Generator vitamins/ 2017-07-17 19:58 - util-0.1.0.scad 2017-07-12 17:53 7.6K tsmthread/ 2019-02-05 17:40 - thread-profiles.png 2019-01-20 02:46 28K seaperch-build-october2011.pdf 2011-11-04 07:45 39M profile-uts.png 2019-01-20 02:46 29K profile-crazy.png 2019-01-20 02:46 60K profile-acme.png 2019-01-20 02:46 21K