Otak provides a visual interface to command line programs that don't have one, that allows users to select arguments from a menu. For example, it can be used as an address book program with Mutt (the default), or as a phone book with SMS sending software, or even as a list of hosts for SSH or FTP.
Webtop is a Web-based POP3 email client that includes SSL encryption, Mozilla support, many email filter options, spam fighting features, custom folders, email import/export, fast searching, undeliverable email bounce, intelligent read receipts, and email-to-PDF generation. The Webtop also includes a calendar, notepad, online file storage, automated email reminders, contacts, mailing lists, and Web-based administration. One installation can support multiple users and each user can set up as many POP3 accounts as they need.
Csv2vcard is a program for converting CSV (comma separated values, as exported by software such as MS Outlook) files containing contact information to the industry standard vcard format, which can be imported by most mailers and PIM software (optimized for Evolution). It's based on a Perl script by Michael MacDonald of Ximian. Csv2vcard can be used to convert any CSV format, not just the English Outlook output.