myWebBasedComputer is currently located on a shared (LAMP) hosting platform from 1and1.com. Users must be prevented from writing server side programs, since a server side program could easily do something like delete everything.
After logging in, a user is directed to a web page which provides a user interface that allows the user to perform file operations on the server.
File editing is done with a html form's textarea. This may be low tech, but it is fast, efficient, and there are apt to be fewer browser bugs.
Despite a wealth of articles, toolkits, and sites pertaining to programming the Web2.0, here are some articles from developers at myWebBasedComputer.