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.
RAPPTOR is a semantic technologies-enabled Web application server for the .Net platform. It integrates relational, hierarchical, and even semantic data structures into a common API and offers broad DBMS connectivity through pluggable drivers. It is designed for rapid application development, a code-driven development style, and platform-independence (Mono and MS .Net 1.0/1.1/2.0/3.0).