PivotX is free software to help you maintain dynamic sites such as
weblogs, online journals and other frequently updated websites in
general. It's written in PHP and uses *flat files* or MySQL as a
database.

Since PivotX is an entirely different beast than pivot-weblog (Pivot
1.x), upgrading from Pivot 1.x will take a while to do properly.
(http://book.pivotx.net/page/4-1)

WWW: http://pivotx.net/