:copen " Open the quickfix window

:ccl   " Close it

:cw    " Open it if there are "errors", close it otherwise (some people prefer this)

:cn    " Go to the next error in the window

:cp    " Go to the previous error in the window

:cnf   " Go to the first error in the next file

:.cc   " Go to error under cursor (if cursor is in quickfix window)