ICAP-server, an (imaginatively-named) daemon which implements ICAP. This seems to be a transcoding proxy server; in other words, it will convert HTML content on the fly, while you browse.
ICAP itself seems to be a protocol for rewriting HTTP responses; in other words, it allows a proxy server to include a small snippet of ICAP client code, and call out to an ICAP server to do the rewriting. Nifty.
Sounds like this could be very handy for low-bandwidth situations; use ICAP to “downshift” web pages into low-bandwidth versions. For example, banner ads can be trimmed out, heavy images converted to small, low-quality JPEGs, etc. One to watch (or help out with).
Ericsson used to have a commercial product which did something similar, but I can’t find it now…