Apps with 'Emacs mode' feature

Karabiner, previously called KeyRemap4MacBook, is a very powerful keyboard remapper for Mac OS X. In addition to simple key remapping, it has special remapping modes like Emacs-mode, SandS-mode (Space and Shift).

Encryptic is an open-source note-taking application heavily focused on encryption. When you start writing, no one will know what you write except for you. We don’t know and we don’t want to know. That’s between you and your work.

mu is a tool for dealing with e-mail messages stored in the Maildir-format, on Unix-like systems. mu's main purpose is to help you to find the messages you need, quickly; in addition, it allows you to view messages, extract attachments, create new maildirs, …