Mason is a tool for building, serving and managing large web sites. Its features
make it an ideal backend for high load sites serving dynamic content, such as
online newspapers or database driven e-commerce sites.

Mason's various pieces revolve around the notion of "components". A component is
a mix of HTML, Perl, and special Mason commands, one component per file.
So-called "top-level" components represent entire web-pages, while smaller
components typically return HTML snippets for embedding in top-level components.
This object-like architecture greatly simplifies site maintenance: change a
shared component, and you instantly changed all dependant pages that refer to it
across a site (or across many virtual sites).

Mason's component syntax lets designers separate a web page into programmatic
and design elements. This means the esoteric Perl bits can be hidden near the
bottom of a component, preloading simple variables for use above in the HTML. In
our own experience, this frees content managers (i.e., non-programmers) to work
on the layout without getting mired in programming details. Techies, however,
still enjoy the full power of Perl.

See also: http://www.masonhq.com/