Spoon is a PHP5 library that focuses on speed, both in page execution and coding agility. Because of its clear and logical structure, it offers a very small learning curve for both the experienced and not-so-experienced developer. Spoon provides a well documented library with a large collection of classes that you can use while building Web applications.
jCores is a Java library that feels like jQuery, with many shortcuts and transparent parallelism. It was made to denoise programming in the Java language and to increase execution speed. Its goal is to demonstrate that Java, the language, can be as sexy as Python in terms of hacking and as parallel as your hardware gets in terms of CPUs.
The Mirror C++ reflection library provides both compile-time and run-time meta-data describing common C++ program constructs like namespaces, types, enumerations, classes, their base classes and member variables, constructors, etc. and provides generic interfaces for their introspection. It also provides several high-level utilities based on the reflected meta-data like a factory generator, which generates, at compile-time, implementations of object factories which can create instances of arbitrary 'reflectable' type.