A microcall is an XML-dialect used to communicate between a client and a server in a standard and easy-to-use way. The client part is (usually) implemented in Java and consists of a simple POJO that can understand the XML messages returned by the server response to a given call. The server part is only responsible for returning standard and correct messages in response to a given call. The server usually does a lot of work when it receives a call, but from the client standpoint, the server only returns a message explaining the result of the call.
Zephyr Basecamp is a functioning GTK frontend and PostgreSQL backend enterprise project that gives small and midsize businesses the same level of inventory, order entry, sales tracking, and accounting functionality as would be expected from commercial applications. It has interfaces for both X11/GNOME/Linux and Windows.
ora_mail is a tool for those of us who do not want to enable JServer for one reason or another. It is implemented as an external procedure that reads message data from CLOBS and passes it to and external program, such as qmail-inject or sendmail. There is also PL/SQL package that wraps arround this procedure to ease message creation.
XMLDB uses an RDBMS to persist arbitrary XML documents. Due to its storage mechanism, searching for and recalling documents is extremely quick. You can also perform XSL translation on documents with surprising speed. The library can be used in any program to store libxml2 documents. A PHP module is also included, making XMLDB into a complete three-tier Web application development suite.