LiveJournal
LiveJournal support in MarsEdit is enabled through the "Blogger-compatible" interface. As such, some of the more advanced features such as mood are not yet supported in MarsEdit.
How to get the API Endpoint URL
At this writing, the API Endpoint URL for LiveJournal is: http://www.livejournal.com/interface/blogger
How to get the Blog ID
Enter your LiveJournal username as the Blog ID.