JSON::Syck - JSON is YAML.
my $data = JSON::Syck::Load($json);
my $json = JSON::Syck::Dump($data);
JSON::Syck is a syck implementatoin of JSON parsing and generation. Because JSON is YAML (http://redhanded.hobix.com/inspect/yamlIsJson.html), using syck gives you the fastest and most memory efficient parser and dumper for JSON data representation.
DIFFERENCE WITH JSON
You might want to know the difference between JSON and JSON::Syck.
Since JSON is a pure-perl module and JSON::Syck is based on libsyck, JSON::Syck is supposed to be very fast and memory efficient. See chansen's benchmark table at http://idisk.mac.com/christian.hansen/Public/perl/serialize.pl
JSON.pm comes with dozens of ways to do the same thing and lots of options, while JSON::Syck doesn't. There's only Load and Dump.
Oh, and JSON::Syck doesn't use camelCase method names.