I just learned that in the PC world (please don't beat me!) a quasi-standard has evolved in which software developers are asked to submit their package meta data. It is an XML file format called "PAD". Here is a description/spec: http://www.padspec.org/
Some benefit is that these files can be read automatically from the server of the software author so that a "ZSI" is just a presentation/search tool for a distributed database.
I know that it has a lot of pros and cons and one is tempted to modify the format to add whistles and belld (there was a discussion about a modification MacPDA initiated by the Mac users by end of 2003).
So I do not want to propose to use it but to get some additional insights which meta-data we can add to ZSI.