CyaSSL is a C-language-based SSL library targeted for embedded and RTOS environments, primarily because of its small size and speed. CyaSSL supports the industry standards up to the current TLS 1.2 level, is up to 20 times smaller than OpenSSL, includes SSL client libraries and an SSL server implementation, includes an OpenSSL compatibility layer, and offers several progressive ciphers such as RABBIT and HC-128. Dual licensed under both the GPLv2 and standard commercial licensing, it caters to a wide range of projects.
Onyx is a powerful stack-based, multi-threaded, interpreted, general purpose programming language similar to PostScript and Forth. It can be embedded as an extension language into other applications, and was designed to have a small memory footprint. It is among the smallest embeddable interpreters available.
NETSHe is a feature-rich and general-purpose Web interface and initialization system for OpenWRT-based firmware. Its main features are network interface management (including point-to-point and wireless), VLANs and aliases, advanced routing (static, multipath, rule-based, RIP, OSPF, BGP), a zone-based firewall, bridges with brouter and filtering capability, interface bonding, quality of service, bandwidth management, traffic shaping, rate control, traffic prioritization, L7 based IP traffic filtering and marking, extended management of wireless interfaces, an access concentrator for variable VPNs (PPTP, L2TP, and OpenVPN), and much more.
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.
db.* is a database management system (DBMS) designed to provide powerful, flexible, high-performance capabilities for developing embedded database applications. By combining the network and relational model technologies in a single system, it lets you organize and access information efficiently, regardless of the complexity of the data. The database has a very small footprint and because it is possible to use the network model to store some of the data, it can be very fast. It is also well-documented and quite simple to learn because of its C-based API.
nMicrocoder is an ncurses EDA tool to write microcode. Basically, it is a stripped down spreadsheet program that lets you fill a table with "0", "1", and "-", and gives you compile-ready verilog code in return. It was written as an alternative to full spreadsheet programs. It is known to run on Linux, IRIX, and Solaris, unless ncurses 5.3 is installed.
elfrc is a program which can turn arbitrary files into ELF object files which can then be linked into your program directly and accessed via simple, user-defined symbol names. Since this is much more effective than turning a binary file into a C array and then compiling that, it's possible to embed even huge (a few hundred megabytes) files directly into the executable and then access the data in constant time without making the compiler or linker eat loads of memory.
The CRT X-Y Library (libcrtxy) allows you to write vector-based video games (like Asteroids, Lunar Lander, and Battlezone from the 1970s and 80s). The end-user (and/or packager of your software) determines how lines are rendered, depending on the capabilities of their system. This choice includes anti-aliasing, alpha blending, blurring, and even the display size and depth. Fixed-point math is used, and sine and cosine trigonometric functions (using look-up tables) are provided. The library is based on libSDL and uses SDL as the video backend.