Caffeine is a free high-performance interoperability solution between the Java platform and the .NET framework, with special emphasis on the enterprise variants of such platforms. It makes software originally written for .NET available to the Java platform. It promotes library reuse between Java and .NET by transferring APIs across environments, and allows code written for one platform to run on the other platform with minimal performance degradation. It is powered by Mono, and runs on Alpha, Linux, Windows, Mac OS X, HPPA, SPARC, and s390 systems.
Java Development Environment for Emacs (JDEE) is an Emacs-based integrated development environment (IDE) for developing Java applications and applets. Features include multiple code browsers, a JPDA-based debugger, method and field completion, template-based and procedure-based code generation, Java source code interpreter, context-sensitive help, and more.
X# (pronounced X-sharp) is an XML-oriented programming language designed to quickly create Web applications and services. Everything is represented as an XML tree, and instead of using functions to manipulate information or perform actions, all possible operations are done by adding, removing, or changing nodes from this tree. Since there are no functions to learn and everything is done intuitively, even inexperienced developers can create complex Web applications and services quickly.