If you run a moderately popular mailing list, you will have to address the spam problem at some point. Many spammers actively target mailing lists, because if the spam doesn’t get caught it will be forwarded to many recipients. The first step is usually to hold non-subscriber posts for moderation. This is good for the list users, but adds a significant burden to the list administrators. It also makes it difficult to approve legitimate non-subscriber posts.

In 2000, I was completing the honours year of my Bachelor of Science at The University of Western Australia. The project was a GAP package designed to help with Markov Chain Monte Carlo spatial problems.

The libxml library provides two interfaces to the parser: a DOM style tree interface, and a SAX style event based interface. Most users of the library choose the DOM interface due to its ease of use, however it does have a few drawbacks. The big drawback is that its memory usage is proportional to the size of the document, which can be a problem for large documents.

In contrast, the SAX interface does not maintain the entire DOM tree in memory, which means that it can be quite efficient for large documents.