Emacs + Vim + Haskell = Yi

Yi does provide great facilities for implementing these features, however. Syntax highlighting is done by proper incremental parsing instead of flaky regexps. Emacs has tried this, but honestly, Emacs Lisp runs way too slowly for this to work. Yi seems to handle pretty big files with good performance, which is very nice to see. Hopefully "extensible" major modes are finally nearby. (If you've ever read cperl-mode.el, you'll see why regexps are a bad choice for implementing syntax highlighting.)

Although it is not my current editor of choice, I think Yi is a better "way forward" than continuing to let the C-based GNU Emacs platform live on. Emacs' great strength is the hundreds of thousands of lines of Lisp code it bundles. Emacs' weakness is that it wants to support that code forever, even though it makes modern features like concurrency impossible to implement. My plan is to add compartments to Yi that will emulate Emacs and run Emacs Lisp code. This will let you edit with simple.el's editing features, or check your mail in Gnus... without having the "real" Emacs around. Then, when you want more modern features, you can start porting the legacy Emacs Lisp code to run on Yi directly. This is better than the usual "let's reimplement emacs" plan of "let's throw away everything!". (This is why you are currently using GNU Emacs or XEmacs and not SXEmacs or the one written in CL. It's too hard to rewrite everything all at once.)