YAJL (Yet Another JSON Library) is a small event-driven (SAX-style) JSON parser written in ANSI C, and a small validating JSON generator. It's highly portable, data representation independent, fast, generates verbose error messages including context of where the error occurs in the input text, can parse JSON data incrementally off a stream, and is tiny.
Jmx4Perl provides an alternate way of accessing Java JEE Server management interfaces that are based on JMX (Java Management Extensions). It is an agent-based approach where a small Web application deployed on the application server provides HTTP/JSON-based access to JMX MBeans registered within the application server. It is set up from a handful of Perl modules, which can be integrated seamlessly in your own programs. It also includes a Nagios plugin, check_jmx4perl, a jmx4perl command line tool for remote JMX queries and operations, and a readline-based JMX shell j4psh, with context sensitive command completion and syntax highlighting.