This is a Ruby module for interfacing with LiveJournal. It's quite thorough — I'm an ex-developer of LiveJournal, so I know the quirks of LiveJournal well, and I've done my best to present a simple and sensible interface.
What might you use it for? The obvious one is writing scripts to post to LJ. But I use it for all sorts of random hacks. For example, I used it to retag a bunch of my old posts: it's a short script to display the post and tags and let you enter new ones, and then with this module it's a few more lines to apply the changes server-side. Here are some other things I've done with this module:
- efficiently synchronize my journal and comments to an SQLite database. [included in the distribution]
- graph relationships between tags in my posts, like Google Trends. [included in the distribution]
- use FUSE (Filesystem in Userspace) to make an "ljfs" that lets me mount an offline copy of my journal and use the normal unix utilities to process entries. [included in the distribution]
- apply machine learning techniques (logisitic regression and support vector machines) to predicting tags on new posts.
See the documentation for more.
The last release I made was 0.3.1 in January of 2007. In 2010, Roman Shterenzon volunteered to take it over. You can find the latest code at his github site.