Roundcube Webmail is a browser-based, multilingual IMAP client with an application-like user interface. Roundcube provides the full functionality you'd expect from an email client, including MIME support, address book, folder manipulation, message searching, and spellcheck. Roundcube is written in PHP and JavaScript.
Java Instant Message (IM) Library, Client and Tools. Flexible framework to design your own. AIM, ICQ, Yahoo, MSN, Jabber, SMS, Nate, GoogleTalk. GUI, spell checking and more. Includes a web interface for remote/cell access. Mac, Win, Linux friendly
Speller Pages is a Web interface and JavaScript library for a server-side spellcheck program. Available in PHP or Perl/CGI versions, Speller Pages allows you to bring the superior spelling suggestion capabilites of GNU Aspell to users of your Web site.
todlc is a text-only client to Diaryland (http://www.diaryland.com) diaries. It is written in perl using only base modules, aims for full cross-platform compatability, and contains such features as offline editing, spell-check, and user-defined editors.
Diom Webmail is a webmail client written in PHP to interact with an IMAP server. Diom Webmail is easily configurable, with common features like sending and recieving messages and attachements, as well as an address book, and spellcheck.