Directories can now be displayed as a 'blog', which treats all file
descendants of the directory as if they were blog entries and attempts
to be somewhat intelligent about how much to show and how to navigate
things, supporting navigation by page date or Nth to Mth most recent
pages.

ChrisSiebenmann doesn't believe this makes BlogDir obsolete. BlogDir is
an excellent view for ChangeLog style situations, which is exactly
what [[.]] uses it for; however, it makes a bad way of displaying a
true blog-style environment because of eventual information
overload. BlogView is designed to deal with that by trimming what gets
displayed and providing time-based and range-based navigation.
{{CutShort}}

Because it looks at all descendants, you can use directory structure
under a BlogView directory to create categorization, or simply to keep
things from being totally overwhelming. (Don't name subdirectories
with the prefix of a VirtualDirectory, though, or various bits of
navigation will stop working.)

The operating structure is much the same as BlogDir: a new view, valid
only on directories, a new renderer called _blog::blog_ to do the
heavy lifting (including deciding where to clip over-long pages), and
a number of associated renderers to provide navigation and
information.

Because you want to display changelog pages somewhat differently from
blog pages, BlogView uses a new template to render pages:
_blog/blogitem.tmpl_. (The name may be unfortunate and perhaps should
be swapped with the BlogDir name.)

When it is cutting the number of items on a page off, _blog::blog_ is
careful to only cut on a day boundary; this keeps by-day navigation
links working nicely, as you cannot use per-day navigation to jump to
the *middle* of a day. Per-day views always show everything from that
day, however large and voluminous. However, the Nth to Mth most recent
view will gleefully cut things off halfway through a day if that's how
it works out.

Navigation renderers make heavy use of VirtualDirs to specify dates or
ranges of pages to show, making them the first time we actually
generate such virtual directory links ourselves. Unfortunately most of
the interesting new calendar-based renderers aren't usable outside of
this view because they rely on having access to the big list of
possible pages so they can grovel out date range information.

There's a variety of new time-of-entry renderers, some of which count
on support from the main renderer to set up context variables for
them.

(Clearly, renderer documentation is going to be a huge swamp.)