At the beginning of the year I wrote an 'Article Manager' web application in Factor. The idea was to have a simple way of writing short articles and snippets of information, that could be tagged and navigated. I wanted something small and easy to use, suited for this purpose. In about 8 hours I threw together the article manager and put a running version at http://articles.bluishcoder.co.nz as a demo.
The article manager system can run multiple sites in a single Factor instance, with each site having its own collection of articles, tags, etc. Multiple users are supported as well as a separation between article authors and site administrators. This is what I originally wrote the basic authentication code for.
I originally wrote it because I maintained a site by hand that had indexed articles and it was getting difficult to update the tags and articles by hand. The site gets a reasonable amount of traffic and I moved it over to a Factor Article Manager system earlier this year and it has been running not stop without problem since.
At the time I didn't put the source in the main Factor distribution but a few weeks ago I tidied it up, got it working with the latest Factor release, and put it in 'apps/article-manager'. Factor 0.89 includes it and after loading the module you can browse the help which explains how to configure it.