There are a lot of ways to use Vim on multiple-files/projects, and the documentation is probably the best place to start.
You can also plug it into Eclipse via eclim http://eclim.sourceforge.net/
There are two plugins which have helped me enormously when dealing with large projects: bufexplorer and nerdtree. Check them out, seriously.
Re:Vim is a great text editor - try it
by iamaleksey on Friday October 02, 2009 @08:40AM
(#856883)
It is good, especially with rails.vim and NERDtree installed. fuzzy_file_finder is super useful as well, can't recommend it enough.
Honestly, my current solution to that is to get my current directory correct when I start (:cd ~/Programming/project) and then just :e app/controllers/users_controller.rb when I need a file. Tab completion makes it fast enough that it's not worth optimizing faster.
Most vi users I know use a combination of gnu screen and bash job control to accomplish this sort of thing.
I.e. how good is it at handling projects, as opposed to just files?