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 RPC URL
At this writing, the RPC URL for LiveJournal is: http://www.livejournal.com/interface/blogger
How to get the Blog ID
Enter your LiveJournal username as the Blog ID.