Todd posted a link on PocketST, but it was 3 yrs out of date so I assume abandoned.
Also one on OOVM but I could not find anything to download.
This sounds intriguing, an IP stack on my calculator :) There is a primitive serial port so browsing is a possibility :)
Any ideas about implementing messages on something like FORTH? JW's pages had a interesting tiny implementation of OOP in FORTH.