json-httpd is a library that provides a web server with JSON-RPC capabilities. The library makes it easy to develop a WUI for application using static HTML and JAVA using JSON-RPC for communication. It also works as a standalone web server.
Jaiwls is a component oriented framework with bundled Servlet-Webserver (Jetty) and HTML Widget library. You can use static compiled java-classes or runtime Groovy-scripts.
PippoProxy is a 100% pure Java HTTP proxy designed/implemented for Apache Tomcat. Thanks to its cache manager (that can be disabled in case of DYNAMIC proxied web sites) it's really very performant in case of STATIC proxied web sites.