QP2M is an Peer2Mail application, which means that it lets you share, store, and manage your files via email accounts. It work similar to other Peer2Mail applications, but it makes upload and download very simple, and has some unique features. You can upload and download multiple files simultaneously, manage your email accounts, and resume transfers after closing the application.
Rogue Detect sends DHCPDISCOVER packets to the network and listens for DHCP servers to respond. It can run continuously as a daemon, or do a single probe and quit. It's written in Perl and can be easily extended to take any action you can think of in response to an unknown DHCP server (send pages, disable them, etc).
Roundcube Webmail is a browser-based, multilingual IMAP client with an application-like user interface. It provides the full functionality you expect from an email client, including MIME support, address book, and folder manipulation. High extensibility is granted by the plugin API and the user interface is fully skinnable using XHTML and CSS 2.