In my work with Feed Digest, one of the constant limitations is the template system. I want users to have as much control as possible over their digests, and while the existing template system hasn't been bad, it's far from ideal.
Currently users can give an optional header and footer template and a 'per item' template. So their per-item template might look something like this:
<p><a href="%URL%">%TITLE,40%</a>.. %DESCRIPTIONPLAIN%</p>
Quite simple. A paragraph for each item in the digest with a link using a truncated title (to 40 characters) followed by a HTML-stripped description. But.. for anything more complex than this, it begins to suck. So, I've invented a language called MoFo. It stands for "Markup Output Format" but the name is as much humorous as practical. It is markup itself, so doesn't have the best name. It'll do for now though. With MoFo you can do things like this:
<% foreach source in sources %>
<p><b><%= source->title %></b></p>
<% foreach entry in source.entries %>
<li><a href="<%= entry->url %>"><%= entry->title %></a></li>
<% end %>
<% end %>
It's basically a more extensive language which will allow me (as well as advanced FeedDigest users) to develop more templates for FeedDigest users in a quicker time. I'll also be able to use it to develop RSS and Atom templates in varying formats, as opposed to the two 'fixed' RSS and Atom templates now. Users will be able to create their own WML/WAP templates, OPML templates, and, well, anything they want on each digest.
MoFo doesn't have much logic in it yet, but this is all being developed right now. Eventually if it has anything to do with feeds and content redistribution in the vaguest, Feed Digest will be the #1 API and developer platform to use. The easy stuff will be even easier, and the complex stuff will now be possible.
More news to come as this stuff begins to roll out..