I'm going to mention this here, because it might be of interest on the
Wikimedia cluster (or it might not).
Last night I deposited Extension:Minify which is essentially a
lightweight wrapper for the YUI CSS compressor and JSMin JavaScript
compressor. If installed it automatically captures all content
exported through action=raw and precompresses it by removing comments,
formatting, and other human readable elements. All of the helpful
elements still remain on the Mediawiki: pages, but they just don't get
sent to users.
Currently each page served to anons references 6 CSS/JS pages
dynamically prepared by Mediawiki, of which 4 would be needed in the
most common situation of viewing content online (i.e. assuming
media="print" and media="handheld" are not downloaded in the typical
case).
These 4 pages, Mediawiki:Common.css, Mediawiki:Monobook.css, gen=css,
and gen=js comprise about 60 kB on the English Wikipedia. (I'm using
enwiki as a benchmark, but Commons and dewiki also have similar
numbers to those discussed below.)
After gzip compression, which I assume is available on most HTTP
transactions these days, they total 17039 bytes. The comparable
numbers if Minify is applied are 35 kB raw and 9980 after gzip, for a
savings of 7 kB or about 40% of the total file size.
Now in practical terms 7 kB could shave ~1.5s off a 36 kbps dialup
connection. Or given Erik Zachte's observation that action=raw is
called 500 million times per day, and assuming up to 7 kB / 4 savings
per call, could shave up to 900 GB off of Wikimedia's daily traffic.
(In practice, it would probably be somewhat less. 900 GB seems to be
slightly under 2% of Wikimedia's total daily traffic if I am reading
the charts correctly.)
Anyway, that's the use case (such as it is): slightly faster initial
downloads and a small but probably measurable impact on total
bandwidth. The trade-off of course being that users receive CSS and
JS pages from action=raw that are largely unreadable. The extension
exists if Wikimedia is interested, though to be honest I primarily
created it for use with my own more tightly bandwidth constrained
sites.
-Robert Rohde