vi and Emacs are two powerful editors that many hard-core or experienced UNIX developers use.
Their keyboard conventions and user-interface are not compatible with those of more recent Windows-like editors (or with each other), and they both require some time getting used to.
Thus, it is recommended that people who have a lot of Windows experience not use them right-away.
Of the various vi clones, the most powerful, popular and recommended is Vim which has a GUI version titled "gvim".
There are two popular and currently maintained versions of Emacs: GNU Emacs and XEmacs.
They are all also available for Windows and for other non-UNIX platforms.