mod_accessibility can be used with mod_proxy as an HTTP proxy to enhance accessibility. Recent (June/July 2003) work has fixed a number of technical problems with proxying, and both a standard proxy and reverse proxy are now running at this server.
Proxying is the hardest task for mod_accessibility, as the range of contents it may encounter is effectively unlimited. In dealing with broken servers and pages, we have the same error-correction task as a browser, but with additional constraints due to dealing with an extra layer (the browser) between us and the user. The proxy should offer positive benefits as often as possible, whilst (more problematically) never being actively harmful even in the worst cases.
One problem when proxying is that the installation default DefaultView, Asis strips out bogus and deprecated markup without substituting anything. This risks presenting users with no contents at all. In view of this, mod_accessibility now defaults to the Medium view when proxying. The Noframes or Betsie view would also do the job.
An accessibility proxy is available at http://proxy.webthing.com/ and can proxy for any HTML page available on the Web by HTTP. The proxy is free for personal use, but is password protected.