jWordConvert is a Java library which can read and render Word documents natively to convert to PDF, to convert to images, or to print the documents automatically. The library is 100% Java, so it can run on any platform which supports Java. It does not use any third party software or native calls, and can be run in a server environment or integrated into a desktop application.
HC-SR04 Ultrasonic Arduino Library is specifically for the HC-SR04 ultrasonic sensor. It features timing, metric conversion, and standard deviation methods, plus a few support methods. It is written in C++ to conserve the namespace. The conversion formula can be easily modified to optimize the accuracy of conversion at different distances for inches and centimeters. Multiple buffers of different lengths can be created for determining standard deviation.
JChartLib is a library for drawing beautiful charts. It supports linecharts and barcharts with colors, automatic axis numbering, and automatic styling depending on the number of values. Charts can be integrated into Java swing applications. Charts can be saved as jpg or png image files.
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.
SourceAFIS is a fingerprint recognition/matching SDK (library), or more generally an Automated Fingerprint Identification System (AFIS). It essentially compares two fingerprints and decides whether they belong to the same person. It can quickly search a large database of registered fingerprints. It comes with an easy-to-use API (pure .NET and Java) plus assorted applications and tools.