Arora is a simple cross-platform Web browser whose feature list includes things like "History" and "Bookmarks". It has a small code base. It was originally created as a demo for Qt to help test the QtWebKit component and find API issues and bugs before the release. A very old version can still be found in Qt's source code in the demo/browser directory. Arora works on Linux, OS X, Windows, FreeBSD, and embedded Linux using Qt Embedded, and works anywhere else Qt does.
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.
Dabo is a three-tier, cross-platform database application development framework, written in Python with the wxPython GUI toolkit. The controls in Dabo's UI are easily bound to data by setting two properties. The business object is designed to afford you complete control over the validation and handling of your data. The cursor classes are abstracted from their backend implementations, allowing for easy support of nearly any backend database. Dabo's design and approach has been inspired by RAD database development tools such as Visual FoxPro, Delphi, and Visual Basic.