Makagiga is an open-source, easy-to-use, portable application for doing a variety of tasks, such as todo listing, text editing, or RSS reading. Plugins are used to implement its various capabilities.
phpPostaci is a POP3/IMAP webmailclient based on Postaci, includes addressbook, notepad and links administration and can create folders for POP3 servers that simulate IMAP folders using MySQL, so can be run in almost any mail enviroment.