db4o is an object database for Java and all .NET environments. Its features include ACID transactions, automatic class schema recognition, query-by-example, a S.O.D.A. object querying API, native queries, LINQ support on .NET, callback methods, memory files, cascade-on-delete, multi-threaded access, and Java Webstart and servlet support.
DirectFB is a thin library that provides developers with hardware graphics acceleration, input device handling and abstraction, an integrated windowing system with support for translucent windows and multiple display layers on top of the Linux framebuffer device. It is a complete hardware abstraction layer with software fallbacks for every graphics operation that is not supported by the underlying hardware.
uClibc (µClibc) is a C library for developing embedded Linux systems. It is much smaller then the GNU C Library, but nearly all applications supported by glibc also work perfectly with uClibc. Porting applications from glibc to uClibc typically involves just recompiling the source code. uClibc even supports shared libraries and threading. It currently runs on standard Linux and MMU-less Linux (also known as µClinux) systems with support for ARM, i386, h8300, m68k, MIPS, mipsel, PowerPC, SH, SPARC, and v850 processors.
PicoGUI aims to be a complete GUI environment for handheld computers and other embedded systems. It uses a client/server model, like the X window system, but while an X server is given raw drawing commands, the PicoGUI server integrates a widget set, making PicoGUI clients small and efficient. PicoGUI also has the goal of allowing client/server connections over a variety of mechanisms. It is most commonly used with Linux, but is designed to be portable to any OS. PicoGUI has a variety of video and input drivers which allow it to interface with the Linux framebuffer device, SDL, the X window system, and several other devices.
libspopc is an easy-to-use POP3 client library written in C. It implements the client side of RFC 1939, providing an easy and quick way to support POP3 and POP3s (SSL) access in a program. It can download email headers and delete messages remotely without actualy downloading the message.
GTK+-DirectFB is a backend for GDK, the drawing kit used by GTK+. Since DirectFB provides drawing functions, a windowing stack, and manages input devices, this is a lightweight GDK port. GTK+-DirectFB is based on GTK+-2.0 and implements the drawing functionality encapsulated in GDK. It allows you to run standard GTK+-2.0 applications on the Linux framebuffer. Due to the use of DirectFB, graphic operations are hardware accelerated if a suitable DirectFB gfx driver is available. Since DirectFB is a very thin library, the memory footprint of GTK+-DirectFB is relatively small.
Device::ParallelPort is a Perl API that allows low level access to the parallel port of most computers. It does this by using a number of drivers, which can be customized and added to, including Linux (direct and parport), Win32, Script, Dummy, and more. It also contains a number of direct access devices including an example printer and a relay controller card.