Luxor is an open-source XML User Interface Language (XUL) toolkit in Java that lets you build UIs using XML and also includes an ultra light-weight, multi-threaded Web server, a portal engine, and a template engine. It is also Web Start-ready, as everything fits in a jar and requires no loose files.
Mireka is a mail server with SMTP, Mail Submission, and POP3 services. It can also be used as an SMTP proxy. As a proxy, it can help to prevent or diagnose mail problems, like outgoing backscatter spam. It provides detailed logging, basic mail traffic statistics, tarpit to prevent email harvesting, and loop detection. It can filter email by DNSBL, SPF, mail size, local domains, and recipients list. Local recipients can be specified using regular expressions. TLS is supported for incoming connections. Aliases, forward lists, and very simple mailing lists can be configured in XML. Custom filters and other components can be written in Java, and they can be easily implemented and installed.
jmemcached is a fast network available cache daemon. It is protocol-compatible with memcached, but written in Java and suitable for applications with portability concerns, where Java is the preferred solution, or for using the memcached protocol in embedded applications with alternate storage engines. Existing clients for memcache work unmodified. It can run as a standalone daemon or be embedded inside an existing Java application.
mod-vhost-ldap is an Apache 2.x module for storing and configuring virtual hosts from LDAP. It supports DocumentRoot, ScriptAlias, ServerName, ServerAlias, ServerAdmin, and SuexecUserGroup directives. It's built on top of mod_ldap, so it uses its caching capabilities and can be used with a threaded Apache httpd.
SwiXAT is a Swing-based authoring tool for the quick and easy development of GUI Java applications. It implements a true MVC framework and uses XML to define the view (SwiXML is used as the XUL engine), BeanShell as a scripting language for the controller, and JXPath as the binding mechanism between the view and model. It provides a complete environment in which it is possible to almost write an entire Java Swing application without writing Java compiled code. The use of XPath makes it very simple to traverse the object tree of the application's business model.