MICHAEL TSAI  It depends on which application you're using. For BBEdit, you would copy the scripts into the Scripts folder inside the BBEdit folder inside Application Support. This page:

http://c-command.com/bbautocomplete/manual-ah/integration-scripts

tells exactly which folders to use.  
(Version 1.5.2)

CHADWITHUHC  i dont get it. ive tried to install this numerous times and i cant figure out how to get it to work. so i copy the scripts into the application support/appnam folders? cause i did and nothing happened... i read the extended online documentation and it still didnt seem to clear this up.  
(Version 1.5.2)

ABHI BECKERT  This is a great app that adds a feature that should be built into all text editors. Not that it matters too much, since it's free.

Installation was a bit alienating though, you'll need to consult the help files to work out how to install it properly, and I imagine newbies would have a hard time understanding the instructions there. But once you've got it installed it "just works".  
(Version 1.3)