kmMail is a PHP-based mail program, based on the mail functionality of Keftamail and is being developed by current Kefta employees. It is meant to be a framework for putting a web-based mail program on your site, but is still robust enough to drop into your current site with little to no modification. The goals of kmMail are MIME compliance, speed, low overhead, and an enjoyable user interface.
R-AddressBook is a Java address book which stores its data in XML format. It can be run on virtually any computer (including PDAs) and offers local and global address information storage, WebServices based synchronization, off- and on-line operation, no restriction on the type or number of fields for each entry, and automatic address updates.