Webmail Pro is a robust, reliable, and feature-packed web-based email client driven by ColdFusion. Webmail Pro offers a whole suite of personalized, database-driven features. [Commercial]
Web IMAP NNTP Gateway, an open source Apache/mod_perl based system which allows users to access email held on an IMAP server via any web browser. [Free]
Multiuser webmail ASP script works like a desktop email client. Includes dynamic tree of folders, attachments, HTML-message display, contact books and search. All information moved/copied from POP3 and stored in database. [Commercial]