Atmail is a fully-featured email server and Webmail client, allowing users to send and receive email via a Web browser or mobile device. It has full support for IMAP mailboxes, and an optional email-server mode that uses EXIM as the MTA. Features include a scheduler, MySQL backend support, spell-check, address book, calendar user preferences, multiple accounts, SpamAssassin support, migration scripts from other mail servers, a customizable interface, an attractive AJAX interface, an optional group sharing Calendar/Addressbook, and an Outlook plugin to sync Contacts/Tasks/Calendar data between a Desktop, Mobile, and Webmail client or other email users.
Brimbox is a database system that was designed to bridge the gap between spreadsheets and custom databases. It is intended to be an alternative to Access and Filemaker. Although Brimbox has its own modular approach, it is customizable in the spirit of Wordpress, though it is a database interface and not a CMS.