4D version 2004.4 or 2004.5 - Mac & Windows
Updated 2/16/07
4D Data Browser is a set of soap methods and a set of web pages that provides the ability to browse 4D datafiles. Try it out and enjoy. The 4D methods are open source and the library actually includes more stuff than is being used by the html browser (see future plans).
If you have trouble you can drop me a line at Julio Carneiro. I'll my best to help you.
Remember that is a version 1.0, so do not forget to backup your structure before even opening it with Insider.
The web side of things was developed with Adobe Flex, a javascript development platform that generates Macromedia Flash applications. Really powerful stuff. It is not open sourced (yet), so if you are interested in the Flex source drop me a line stating where you want to take it.