Fan is an OO, functional programming language designed to cross compile to both the Java and .NET platforms. It provides a concise syntax along with elegant, cross portable libraries.
Nailgun is a client, protocol, and server for running Java programs from the command line without incurring the JVM startup overhead. Programs run in the server (which is implemented in Java), and are triggered by the client (written in C), which handles all I/O.
Jaskell is a functional scripting programming language that runs in JVM. The name "Jaskell" stands for Java-Haskell, but it is not haskell 1. Most of the current scripting languages are Object-Oriented. Though they more or less have functional tastes (Ruby's sexy closure, for example), the heart of them are still Object-Oriented. One of the most important essenses of functional programming (combinators) is yet to be brought into Java. 2. Jaskell brings with it higher order function, function currying, pattern match and monadic combinator support. 3. Monadic combinator is ideal for designing Domain Specific Language. It is relatively easy to tailor Jaskell runtime to make domain specific syntax look like simple atomic statements. See Neptune for a real example. 4. Jaskell is nothing but a Java library that passes Java objects in and out of the interpreter.