Highlight a block of text and hit ,# and it is commented out in perl.
" , #perl # comments map ,# :s/^/#/<CR> " ,/ C/C++/C#/Java // comments map ,/ :s/^/\/\//<CR> " ,< HTML comment map ,< :s/^\(.*\)$/<!-- \1 -->/<CR><Esc>:nohlsearch<CR> " c++ java style comments map ,* :s/^\(.*\)$/\/\* \1 \*\//<CR><Esc>:nohlsearch<CR>