XmlBlaster is XML based MOM (Message oriented Middleware) with a lot of features. It is a publish/subscribe and point-to-point MOM server which exchanges XML-encoded messages. Communication with the server is based on CORBA (using JacORB), RMI, XML-RPC, native socket, or a persistent HTTP plugin. Subscribers can use XPath expressions to filter the messages they wish to receive and add their own MIME-based filter plugins. C/C++, Java, Perl, Python, VisualBasic.net, C#, and PHP client demos are included in the xmlBlaster test suite, and Tcl and Python demo clients are scheduled. XmlBlaster also provides a browser callback framework, allowing browsers (Netscape, Mozilla, MSIE) to receive instant callbacks over a persistent http connection. A security plugin framework allows authentication/authorization in many ways. Currently there are LDAP- and passwd-based plugins available.
xmlrpc-c is a programming library for writing an XML-RPC server or client in C or C++. XML-RPC is a standard network protocol to allow a client program to make a simple remote procedure call (RPC) type request of a server. It's like SOAP or CORBA, but much simpler. This library speaks the same XML-RPC as similar libraries for lots of other programming languages, with most of the popular extensions. The client library uses either w3c libwww or Curl for HTTP. The server library contains a complete lightweight HTTP (Web) server and also facilities for running with CGI under any Web server.
SPOPS (Simple Perl Object Persistence w/ Security) is a robust and powerful Perl module that allows you to serialize objects. It is unique in that it also allows you to apply security to these objects using a fairly simple but powerful scheme of users and groups. It's also unique in that for most objects, you will not need to write any code. All you need is a fairly simple configuration file, and you can have a class for your object ready to go, right out of thin air.
The SOAP to CORBA bridge/translator is written entirely in C++ and shows that it is indeed possible to do a generic translation of SOAP requests to CORBA method invocations and vice versa. This is implemented by using the CORBA Interface repository to match the incoming SOAP request to the corresponding CORBA service, build the dynamic invocation of the CORBA service, and generate the SOAP response (or possibly SOAP fault in the case of a CORBA user exception, for instance).
XPLC is a component system that tries to enable the use of components in a pervasive way. It aims to be easy to use, have low speed and size overhead, and be language and platform neutral. Basically, the idea is to leave no excuse for an application not to be component-enabled (being a component and/or using components).