Regarding Trackback and PyCS/PyDS: the problem here isn't the server software, it's more the site structure. PyDS generates no single posting pages like MoveableType or other systems do, it generates multiple postings pages (and archive pages) like Radio does. The problem here is that trackback autodiscovery based on HTML only works good if you have one posting per page, as the client software can't know which of those multiple postings to refer by what trackback URL. So PyDS doesn't generate autodicovery for trackback. But PyDS does add trackback:ping headers to the RSS feed, so aggregators should be able to get the trackback URL for individual postings from there. The trackback URL for entries is the same to ping as to see the trackbacks. So if you wan't to trackback one article, just use the "trackbacks" link and add that individually to your posting to ping. This might be possible with Typepad, but I don't know much about Typepad - but it is possible with moveable type, at least if you disable the autodiscovery stuff.