Vim:Quickfix
Feature
-  :copen: Open the quickfix window
-  :ccl: Close it
-  :cw: Open it if there are "errors", close it otherwise (some people prefer this)
-  :cnext,:cn: Go to the next error in the window
-  :cc: Go to current error in the window.
-  :cnf: Go to the first error in the next file