I can successfully sign in with an old version of
Semagic (1.5.8.3U) once I changed the default port number to 80 in the server settings (and the API to MetaWeblog, of course). No category list shows - trying to refresh the list pops up "Error parsing response XML".
EDIT: Posting goes fine, but can't edit old entries - the titles listed are correct but the entry bodies are all blank. May be a bug in Semagic; if so, may be fixed in less ridiculously antiquated versions. Must upgrade to determine cause of bug.
Son of Edit: Current version (1.7.0.9U) also has blank entry bodies when attempting to edit existing posts. Suspect Tabulas' implementation of API not quite matching what Semagic expects. Will test more clients; if most-to-all have same bugs, will make list of copy-pasted error messages received and ask Roy to puzzle over that.
My trial of BlogJet expired so cannot try it on new API. Not particularly bothered by that.