ustr (Micro string library) is a string API for C. It has tiny overhead over just plain strdup(), is much safer, is easier to use, is faster for many operations, can be used with read-only or automatically allocated data. You don't even need to link to the library to use it (so there are no dependencies).
v4l-utils is a collection of various video4linux (V4L) and DVB utilities. libv4l is an accompanying collection of libraries that adds a thin abstraction layer on top of video4linux2 (V4L2) devices. The purpose of this layer is to make it easy for application writers to support a wide variety of devices without having to write separate code for different devices in the same class. It consists of 3 different libraries. libv4lconvert offers functions to convert from any (known) pixel format to V4l2_PIX_FMT_BGR24 or V4l2_PIX_FMT_YUV420. libv4l1 offers the (deprecated) v4l1 API on top of v4l2 devices, independent of the drivers for those devices supporting v4l1 compatibility (which many v4l2 drivers do not). libv4l2 offers the v4l2 API on top of v4l2 devices, while adding support for the application transparent libv4lconvert conversion where necessary.
vCard4J is a complete toolkit to manipulate vCards (RFC 2426) in Java. It contains a parser to read vCard files. It also includes a compiler to extend the library. vCard types are defined in a XML file, making it easy to add custom types. It also contains XSLTs to convert the internal DOM structure into vCards 3.0, xHTML, or other formats.
vlogger is a logger daemon for Apache. It will accept piped logfile input, split it according to its corresponding virtual host (using a file cache to avoid resource limitations), and write it to disk. It automatically rotates all files and tracks them using timestamps. It is intended as a replacement for cronolog.