OpenEJB is a simple, lightweight Enterprise JavaBeans (EJB) container and server. You can embed OpenEJB in your own applications, or in a Web application server like Tomcat, or run it as a standalone EJB server. It supports EJB 3.0, 2.1, 2.0, and 1.1, and has partial support for EJB 3.1.
OAF is the Object Activation Framework for GNOME. It has a similar purpose to gnorba, the GNOME 1.x CORBA activation library, and will replace it for GNOME 2.0. It allows you to do much more powerful activation queries than gnorba. Each server is described by an XML file that defines its attributes. When querying or activating, one may specify complex requirements using the OAF query language.
ACDK is a development framework with a similar target of Microsoft's .NET or Sun's ONE platform, but it uses C++ as a core implementation language. It implements the standard library packages, including acdk::lang, acdk::lang::reflect, acdk::util, acdk::io, acdk::text (including regexpr), acdk::net, acdk::sql, acdk::xml, and more. Flexible allocator/garbage collection, threading, and Unicode are implemented in the core of ACDK. Extensions make C++ objects available for reflection, serialization, aspect-oriented class attributes, and [D]ynamic [M] ethod [I]nvocation. This DMI acts as an universal object oriented call interface to connect C++ with scripting languages (Java, Perl, Tcl, Python, Lisp, Visual Basic, and VBScript) and standard component technologies (CORBA and COM).