In Linux it's more likely that extensions to existing editors will be more mature than entirely new ones. Thus, the two stalwarts (vi and emacs) are likely to have packages available.
EDIT: Indeed, here's the vi one:
http://vim-latex.sourceforge.net/
... and here's the emacs one:
http://www.gnu.org/software/auctex/
I have to say, I'm a vi man, but the emacs package looks rather spiffy: it includes the ability to embed preview images of formulas in your emacs buffer.