I want to create a CGI/PHP interface for a program I'm working on, but really don't know where to begin as I have never worked with it before. I'm hoping there is an existing open source framework, or at least some good examples.

Essentially, I am looking to create something very similar to the interface that is common on any standard wireless router. It will have a few tabs, be able to load/parse data from text files stored on the system, be able to run shell commands on the local device, etc.

I've found LuCI, which is precisely what I'm looking for...except it is intended for embedded devices and uses Lua.

I'm looking for something that could be dropped into any modern HTTP server (Lighttpd, Apache), and just work without the user having to install anything unusual.

Any ideas?

I don't understand the question. "How can I create a PHP/Javascript/HTML website that looks like a wireless routers and that doesn't require third party PHP libraries to be installed?"

Instructions for doing tabs in CSS are everywhere.

You mean it will have forms with <input type="upload"> buttons? And file upload handlers on the backend? Isn't this covered by the official PHP docs?

Have fun writing the parsers in PHP.

That will have to be done server-side. The server will provide a URL that will execute the shell commands when POSTed to. The client-side code (which can just be a POST form) can then POST to that URL. You don't need to use CGI for this.

I'm not sure how I can word the question any better.

Log into any home router, and look at the interface. I want to do that, but without having to actually write it all from scratch.

The only project I have been able to find so far is actually targeted for routers and other embedded devices, and relies on things like haserl. I'm not actually going to run this on an embedded device, so I am looking for something that doesn't require that.

You're going to have to write it from scratch.

It seems blatantly impossible that nobody has ever published a framework or template for developing a web-based software user interface, and every time anyone has ever wanted to do one they started with a completely blank slate. I can find thousands and thousands of templates for web sites, but nobody has ever done even one for a UI?

I guess I will just keep looking.

A framework for developing one is quite different from a prebuilt one. There are plenty of frameworks for developing them, one of the newest and most buzz-worthy of which is the Twitter Bootstrap.

If I were to do this, my first choice for a technology stack would probably be Twitter Boostrap and meteor.js. Meteor doesn't fit your requirement of not requiring any dependencies though.