c:\@Work\Perl\monks>perl -wMstrict -le
"use Data::Dump qw(dd);
 ;;
 my ($kw) =
   map  qr{ (?i) (?: $_) }xms,
   join q{|},
   map  quotemeta,
   reverse sort
   qw(.NET C C++)
   ;
 ;;
 my $title = 'C xC Cx C C C C++ xC++ C++x C++ C++ C++ .NET x.NET .NETx .NET .NET .NET c c++ .net'
 ;;
 my %count;
 $count{ uc $1 }++ while $title =~ m{ (?<! \S) ($kw) (?! \S) }xmsg;
 dd \%count;
"
{ ".NET" => 5, "C" => 5, "C++" => 5 }