As of July 2009 the lightweight web browser abaco is now distributed as part of the stock Plan 9 distribution. It is a web browser that started as a rewrite of webpage, with many new improvements including tables support. A testing snapshot can be found at: /n/sources/contrib/fgb
webfs(4) and html(2) were written at Bell labs as the backend for a new web browser; unfortunately the project stalled. Aki Nyrhinen has since written a simple frontend called webpage for these which does an amazingly good job of rendering basic web pages; it also makes interesting use of the plumber to support hyperlinks. This work also stalled and has been superseded by abaco.
HGET | HTMLFMT
The plan9 tools hget(1) and htmlfmt(1) can be used to fetch and render simple web pages but are most useful for scripted fetches (e.g. ap(1))
VNC TO WINDOWS OR *NIX
The best way to get a fully supported web browser under plan9 is to use the vnc client to connect to a linux or Windows box. This performs very well if used over a fast network connection.