(
http://www.csie.ntu.edu.tw/~fuh/fcourse/norton4/paper/Got%20...)
> It is based on the world's smallest implementation of a TCP/IP stack -- which is implmented on a small 8-pin low-power microcontroller .. using a mere 512 words of program ROM. If IPic can fit in a PIC, it can fit in just about anything.
> The TCP/IP code itself fits in about 256 bytes (12-bit), and the rest is some extra salt-and-pepper and miscellaneous code.
> The chip is a PIC 12C509A, running at 4MHz (Internal RC clock).
> implementing the IPic tiny TCP/IP stack,
> a HTTP 1.0 compliant web-server,
> a simple telnet server (for editing files on the chip),
> an 24LC256 i2c EEPROM
I think someone has done something smaller by now.
--- EDIT
Here are some other tiny devices.
(http://d116.com/ace/) - "the webACE: a Fairchild ACE1101MT8 microcontroller programmed as a Web server and containing two tiny web pages in its on-chip memory. Since the ACE1101MT8 is the smallest available microcontroller, I believe that this really is the World's Smallest Web Server."
(http://www.magic-1.org/) big, but home built CPU. "This web page is being served by a completely home-built computer: Bill Buzbee's Magic-1 HomebrewCPU. Magic-1 doesn't use an off-the-shelf CPU. Instead, its custom CPU is built out of ~200 74 series TTL chips."
(http://kl.net/atari/) no longer serving pages, this was a web server on an Atari 800