What type of program is this called?
I've been searching and searching and asking around, but I can't find an answer. There are programs that seem to be able to act as servers on localhost while they run and produce pages in memory that
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I've been searching and searching and asking around, but I can't find an answer. There are programs that seem to be able to act as servers on localhost while they run and produce pages in memory that allow the user to interact with this program.

Examples of them are: "Mediacoder" and "K9 Web Protect".

Please tell me what kind of programming I need to lookup in order to accomplish the same tasks as these programs. That way I can actually have a direction when I'm googling it in C# or Java or whatever. All answers are welcome on this one.