LibU is a multiplatform C library that comes under a BSD-style license. It includes many interdependent modules for accomplishing several tasks: memory allocation, networking and URI parsing, string manipulation, debugging, and logging in a very compact way, plus many other miscellaneous tasks. It has a small footprint (about 70KB for the default configuration), it is modular, and it has a multiplatform nature, making it an ideal candidate for embedded systems. KLone is an example of such usage.
Sql2xml is a CGI program that lets you request a SQL query and convert it to JSON, CSV, XML or INI through a Web server. Sql2xml supports requests from multiple users and for multiple databases. It is intended for developers who do not have direct access to database servers due to firewalls or other restrictions.
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.
Clover is a Java code coverage analysis tool. Key features include per-test code coverage, test optimization (aka selective testing), interactive and historical HTML reporting, IDE integration with Eclipse, IntelliJ IDEA, RAD, and NetBeans. It also works with Ant, Maven, and other command line tools.
Uhura is a Web console for databases. It works with MySQL, PostgreSQL, and FirebirdSQL. It presents trees that let you browse databases, tables, columns, constraints, triggers, views, and procs. It has panels for history and fragments. Its editor features autocompletion and autoindenting. It is easy to install.