XSA: A quick introduction

What is XSA?

XSA is an XML-based system that allows anyone who is interested to discover new versions of software products as they are released automatically by polling XML documents describing the products. It is mainly intended to help software index maintainers keep their indexes up to date.

Why do we need it?

If you've ever used a site that collects links to software products or created a software product yourself you probably know already why this is needed. Most software products are usually listed in several different lists, which means that for the author, keeping all of them up to date is a lot of work. Often, the author is not even aware of all the lists that mention his product.

Things are only slightly better for those who maintain the lists: ideally they should check every day for new releases and moved products, but in reality this is far too much work when the products number in the hundreds and thousands. Most list maintainers solve the problem by never checking the entries at all, others check very rarely.

How does it work?

It's really simple: every software maintainer publishes a small XML file (the XSA document) which lists that maintainers software products, version numbers and relevant addresses.

Any maintainer of a software list that knows the URL of the XSA document can then set up a program to automatically check the XSA document for new releases and changes to product names and addresses.

Who made XSA?

XSA was created by me, Lars Marius Garshol, with valuable input from James Tauber and Robin Cover. I use it to keep my list of XML tools up to date, and it was for this reason that I started this project originally.

The DTD, API and checking model are expected to remain stable, although the system may be extended later if the need arises. Backward-incompatible changes will be avoided as far as possible.

Comments, whishes and bug reports are all welcome at larsga@garshol.priv.no.

Who uses XSA?

This is a list of all the XSA users that are currently known to me:

Who has published XSA documents?

This is a list of all the XSA documents known to me at the moment:


2000-06-06, Lars Marius Garshol, larsga@garshol.priv.no.