This is where I will post code snippets and experiments. Most of the code I have shared so far is JavaScript/jQuery, but I also hope to share code in other languages and platforms (such as C# (WebForms/.NET Core), PHP, Vue etc).
I have a GitHub repository with old jQuery Plugins, some haven’t been updated for 10 years, though they may still work in most cases with only minor tweaks. The exceptions are a few split off from the main repository at the start of 2016 - jquery-numeric and jquery-checkboxes. I would recommend an alternative plugin such as maskMonkey instead of jquery-numeric, or using the pattern attribute (w3schools.com) on inputs.
The plugins were developed when there was not much choice with client side development and we were limited to a few web browsers (Chrome, IE 8, Firefox) and nothing significant on mobile platforms. They are still on there for historic purposes and if anyone is curious on one way of developing plugins back when jQuery was in its infancy and unlikely to be developed further (I don’t use them myself). I started development with jQuery using a beta version, where discussions were in the jQuery (English) and jQuery Plugins Google Groups.