EDIT: JQuery is a library of JavaScript code for the web that's been around forever and is very widely used.
Back in 2007 when I first built UruTunes.com as an exercise to teach myself web publishing and development, the web was a chaotic, wild-west kind of beast. Coding standards had not yet been established to the level we have today and that made publishing for all the different browsers and operating systems quite challenging.
At first I didn't want to use JQuery and rely on someone else's code, but I quickly learned that it really shined at flattening the playing field across various systems, and allowed me to do things I couldn't without it. So, I learned it and used it where needed, and it did well for that purpose.
Now, web standards have come a very long way and systems have become more predictable and easier to manage. This means that there isn't much need for JQuery or similar libraries, so I've cut the cord and rewritten all the code in UruTunes.com's "front pages" (non-forum stuff) to work without it. It's invisible to our users, but gives me a warm fuzzy.
However, this forum software, called phpBB, still uses JQuery and likely will far into the future, which makes sense considering the complexity and capabilities of it. I have no problem with that since there's lots of brilliant nerds keeping it up to date and working great. I house and manage all the code on my own servers, and that comforts me knowing I'm in control.
As always, please let me know if you have any problems, questions, or any other input. I love hearing from the community.