I just released a reverse proxy server on github:
You can also just download the war file.
Suppose there is company or a country which blocks site a.com and that you want to go around that restriction. One way is to create a new site say b.com which is not blocked. Whenever a user visits b.com, their request will be directed to a.com, and the response is presented back to the end user. b.com is called a reverse proxy.
Apache already has a reverse proxy module, however, this module has to be enabled by the server administrator. I wanted something more flexible.
The reverse proxy presented here is just a WAR file which can be deployed to any Java servlet container like Tomcat.
This proxy is already in production helping users in two counties go around their governments restrictions.
I am aware of at least one similar project j2ep, however it seems that it has not been updated for several years.