mod_proxy_html is an output filter to rewrite HTML links in a proxy
situation, to ensure that links work for users outside the proxy.  It
serves the same purpose as Apache's ProxyPassReverse directive does for
HTTP headers, and is an essential component of a reverse proxy.

Note (for apache24 users):
mod_proxy_html has now been relicensed and incorporated into the core
Apache HTTPD distribution at apache.org from HTTPD 2.4. That version is
now likely to be more up-to-date than this one.

WWW: http://apache.webthing.com/mod_proxy_html/