I have been using the [Codemirror] highlighters for years on this site, and now it is nearing the time to step away from it and start using my own system.
I have been working on a Server-Side Script for highlighting code for the last week and am nearing completion of the first step.
I say first step because this will be an ongoing project that will be updated as needed or when I decide to add something extra.

You will be able to tell when it is released to the site, as the site name will appear on the header border of the SynTax highlighter.

Since it is not JavaScript-based like Codemirror, it will not have the same bandwidth overhead as I have seen with Codemirror.
It uses the most updated version of JQuery/3.7.1/jquery.min.js that is hosted on my server, so not to cause any other bandwidth lags when there are internet issues on either side.
42 lines of JS code are placed at the page's bottom. Besides that, no extra JS libraries are required to run the code. There are some limitations that I will have to do some research on, but I do not think it will be that huge of a deal.

Will I be releasing it?
I have been thinking about this, but it will not be released to the public at this moment. If I decide to release it in the future, I will determine if it will be open-source or paid.
I love the idea of having it on a site such as GitHub for a community-supported project, but right now, it is just a passion project I've wanted to do for years, but never knew how to start. And knowing what I know now about what you can do with Server-side coding, such as ASP Classic, ASP.NET, along with PHP, Python, Perl, and others

Currently, the code only runs on Classic ASP/VBScript, as that is my development code of choice, but I will port it to ASP.NET C# and VB.