PAR is a cross-platform packaging and deployment tool, dubbed as a cross between Java's JAR and Perl2EXE/PerlApp. It can turn your Perl programs into ready-to-run executables, build and use PAR files into @INC to avoid version conflicts, turn CPAN module distributions into PAR distributions, or install/uninstall/sign/verify PAR distributions.
JSON::XS implements JSON for Perl. Unlike other modules, its primary goal is to encode to syntactically correct JSON and flag invalid JSON while decoding. It ensures round-trip integrity of data types while being intuitive to use. Currently being the fastest of the JSON encoders available for Perl, it supports a variety of format options, such as single-line, ASCII-only, or pretty-printed, and can be tuned for speed or memory usage. It comes with a wealth of documentation describing usage and implementation details.