Spring is a lightweight Java/J2EE application framework based on code published in "Expert One-on-One J2EE Design and Development" by Rod Johnson. It includes powerful JavaBeans-based configuration management applying Inversion-of-Control principles, a generic abstraction layer for transaction management allowing for pluggable transaction managers, a JDBC abstraction layer, integration with Hibernate, JDO, Apache OJB, and iBATIS SQL Maps, AOP functionality, and a flexible MVC Web application framework with multiple view technologies. There is also a .NET port available.
Apache .NET Ant Library is a library of Apache Ant tasks that support development for the .NET platform. It supports Microsoft's frameworks as well as Mono. The library contains tasks to run common .NET development tools like NUnit, NAnt, or MSBuild. In addition, it contains a task to create Windows MSI installer packages using the WiX toolkit. The "old" .NET development tasks of Ant's core have found a new home here as well, and further development of those tasks will happen inside of this Ant Library.
AsDoclet can be used to generate Actionscript and C# files out of Java sources. Such a tool is useful for RIA and client/server applications where value objects are transmitted between server and client as serialized data that should be deserializable on both ends again. That includes remoting technologies like Flash Remoting, RTMP, Blaze DS, Red5, and Hessian.
SharpTAL compiles XML-based templates to .NET assemblies. It contains a complete implementation of the Zope Page Templates (ZPT) language, a system which can generate HTML, XML, or plain text output. ZPT is formed by the Template Attribute Language (TAL), the Expression Syntax (TALES), and the Macro Expansion Template Attribute Language (METAL).