WareLogging, VimEditor, PerlLanguage. = perl compatible regular expressions = [http://vim.sourceforge.net/tips/tip.php?tip_id=393 Perl compatible regular expressions]. For most of the one-off expressions you'll ever write, there's a way to do what you want in vim. That said, if you're used to Perl, translating between the two dialects becomes painful for anything much beyond a simple search and replace. Instead: # Verify in :ver that +perl or +perl/dyn is compiled in. # Install Perl if necessary. On Windows, ActivePerl is required. # Type :perldo s/searchme/replaceme/g Or: :%!perl -pi -e 's//\n/' On Debian, you can apt-get install vim-perl <[Brennen]> When using perldo to perform substitutions, keep in mind that $_ is set to the current line ''without'' a newline - so if you're expecting whitespace at the end of the line, you may not find it. This works, though: :perldo s/(http\S+?)(\s|$)/"$1"$2/g Note the (\s|$).