Vim

Vim (available at http://www.vim.org/) is the other heavyweight in this category and an old rival to Emacs. So if anyone is talking about Emacs or Vim, the name of the other will invariably crop up. The guiding philosophy behind Vim is again the use of keyboard exclusively, and the biggest advantage of Vim is that it is often available on servers to be used through SSH. So, for example, when you want to deploy something on AWS (Linux) machines, all you'll find on that machine is the omnipresent terminal (the command line) and Vim, so if you are not proficient with both of these, you are going to have a tough time and will most likely have to install a simpler editor like Nano (available at http://www.nano-editor.org/) to edit anything. Vim has an insert mode where the user enters text and a command mode to navigate and edit using keystrokes. Because of a dedicated command mode, Vim has more commands which consist of single keys rather than a key combination. Hence, one can edit faster when one has become accustomed to those commands. Again, Vim also has a steep learning curve but pays you rich dividends because it too supports most of the programming languages, and so you'll hardly need to think about other editors (not to mention that it is also free).