Is There A Standard for Software Metadata?

tagish asks: "I'm sitting here preparing some Java source to release under the GPL and wondering how best to tell people about what I'm doing. It seems to me that there's a compelling need for a simple, extensible standard for software metadata -- an agreed way of describing any piece of code, what it does, who made it, what license(s) it's available under, what platforms it supports, what it is compatible with and so on. The first question then is: does such a standard exist? And if it does why is it not more popular?"

"It's one thing to make this stuff available, but if people can't find it I'm wasting my time. Of course there are places I can go to publicise what I've done (Freshmeat, Jars, Gamelan, and Servletcentral in this case) and those services perform a valuable function, but in practice it is still quite hard for someone to find some code in language X that performs function Y in a way that complies with constraint Z. There's no search engine that finds reusable code based on variable criteria and, given the number of incompatible ways source code can be packaged, described and distributed, little prospect of anyone building one.

Right now, when I release this code, if I want people to find it I have to:

• write a description of it
• set up a home page for it
• register that page with numerous search engines possibly using the description I wrote
• visit the appropriate repository and announcement sites making submissions at each
• find out whether there's an appropriate usenet group and post to it

Assuming that such a standard doesn't exist does anyone want to get together with me and devise one. I'm thinking of something (human) language independent, simple, capable of encompassing all types of code, amenable to automatic processing. What about it?"

As much as I agree that something like that should exist, I believe that if you feel strongly about your code, then a home page is a must for your project (as well as writing descriptions about your project and registering it with search engines). A metadata standard would be a big help in this respect, but it's not going to be a replacement for going out there and spreading the word yourself as best you can.

With that said, what current data formats could be extended to serve as such a metadata standard, and if none of them are completely sufficient to handle this type of application, what would such a format need to be robust and flexible enough to serve this purpose.

Comments

Check out Project Meta.

[Q*bert]

It is a very ambitious project. The goal is to make a single format not only for project metadata but also for package metadata, abstracting over RPMs, debs, ports, and the like. The leaning is toward making it XML-based.

The leader of the project, SF Perl Mongers' own Rich Morin, is being very circumspect about it, trying to gather lots of information from experts in different OSs and distributions, and of course working on it in his free time, so the product is not there now--but if you're interested in contributing to such an effort, this would be the place to help out.

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Well...

[Wdomburg]

I'm not aware of one that is cross-platform, though there is one for Linux called the "Linux Software Map."

The format includes the following fields:

Title
Version
Entered-date
Description
Keywords
Author
Maintained-by
Primary-site
Alternate-site
Original-site
Platforms
Copying-policy

Given that there is a platform field, despite it being refered to as the *Linux* Software Map, this does qualify on most of the criteria that you mentioned.

Freshmeat, though not a format, is also a fairly comprehensive database of software which provides much the same information as you mentioned, including:

Title
Description
Author
Licence
Category
Download
Packages
Homepage
Changelog

Freshmeat, aside from providing updates on their site, also provide them via text files, which are suitable for simple automated parsing.

Though neither solution is entirely perfect, both are definitely close to what you're looking for.

What I would like to see is an SQL backend, with a simplified query engine on top of it that returns an XML formated document back. This would take care of the extensibility portion of it, as fields could be added to the backend and XML format, without breaking compatibility with the client.

Likewise, I would like the database to be available as a download so that mirrors could be created and/or alternative front-ends.

(E.g. The search functions of Freshmeat aren't always flexible enough for me to easily pinpoint what I am looking for. I would definitely prefer being able to download a snapshot of the database and run custom SQL queries locally.)

In any case, freshmeat and lsm are likely your best choices for the time being.