The "FAQ" link below the description leads to:

"Chennai Central is a bandwidth saver plugin that makes your wordpress site support conditional GETs by search engine crawlers , feed readers and more."

(followed by more detail about what conditional GETs are, and why they help)

For me the FAQ was empty, maybe a compatability problem with Android's browser. I'll check it out on a real computer.

Never mind the FAQ, the "Download Now!" link is a 404.

I'm kind of surprised that in 2010 stock Wordpress would not have this kind of cache-friendliness built in.