SWeTE is an HTTP reverse proxy that provides website translation. You can set up proxies for any sites, then connect a translation memory to the site to have it translated into any language. It provides a web-based translation form, and an option to translate strings using Google's translation API.
ModSecurity is a web application firewall that can work either embedded or as a reverse proxy. It provides protection from a range of attacks against web applications and allows for HTTP traffic monitoring, logging and real-time analysis.
J2EP is a reverse proxy running on a J2EE engine. The proxy is written in java and was originally designed with Tomcat in mind, but any engine should work fine. A set of basic mapping rules are included but they can easily be extended to your own needs.
jRevProxy is a lightweight reverse proxy server fully written in Java. jRevProxy accepts HTTP and HTTPS requests and translates these into new requests based on a set of rules. HTTPS with client side authentication (X509 certificates) is supported.
Next generation reverse proxy : provides authentication and authorization services for all incoming HTTP traffic, in addition to offering transparent web SSO to protected applications.
Oroena is a fully Java 2 Enterprise Edition powered Open Source Reverse Proxy engine. It provides unique session, security or server access management for a multi-server architectured portal.