Kaya: A statically typed, imperative cross-platform programming language with type inference, powerful data description capabilities and built-in abstractions and libraries for easy and robust web application development. http://kayalang.org/
retawq is a multi-threaded web browser for text terminals on Unix-like computers. It is fast, small, nicely configurable and comfortable; e.g. you can keep open as many "virtualwindows" as you want and work simultaneously in two of them.
nsjava is a loadable c-module which embeds a java virtual machine in aolserver. This module is being developed to support the openacs project - see http://openacs.org, but it could find general application as a web development tool.