EO is a templates-based, ANSI-C++ compliant evolutionary computation library. It contains classes for any kind of evolutionary computation (specially genetic algorithms) you might come up to. It is component-based, so that if you don't find the class you need in it, it is very easy to subclass existing abstract or concrete class.
esky is an implementation of job freezing (checkpoint/resume) for Unix processes. It can save the state of a running process to disk then later resume it from the point it left off, possibly on a different machine. esky currently works on a limited but non-trivial range of processes. esky can cope with programs that open or mmap() files, including opening shared libraries with dlopen(). esky is implemented entirely in userspace - no kernel patches or modules are required. It works under Linux 2.2 and Solaris 2.6 and is written to be independent of CPU type.
eXist is a native XML database featuring efficient, index-based XPath query processing, extensions for keyword search, XUpdate support, and tight integration with existing XML development tools. The database is lightweight and may be easily deployed in a number of ways, running either as a stand-alone server process, inside a servlet engine, or directly embedded into an application.
Linux, in the tradition of UNIX-like operating systems, implements file system permissions using a rather coarse scheme. While this is sufficient for a surprisingly large set of applications, it is too inflexible for many other scenarios. For that reason, all the major commercial UNIX operating systems have extended this simple scheme in one way or the other. This is an effort to implement POSIX-like Access Control Lists for Linux. Access Control Lists are built on top of Extended Attributes, which can also be used to associate other pieces of information with files such as Filesystem Capabilities, or user data like mime type and search keywords.
f2py is a command line tool for binding Python and Fortran code. It scans Fortran 77/90/95 code and generates a Python C/API module that makes it possible to call Fortran routines and to access Fortran data (COMMON blocks and Module data) from Python. No Fortran or C expertise is required for using this tool.
FLTK (pronounced "fulltick") is a cross-platform C++ GUI toolkit for UNIX/Linux (X11), Microsoft Windows, and Mac OS X. It provides modern GUI functionality without the bloat, and supports 3D graphics via OpenGL and its built-in GLUT emulation. FLTK is designed to be small and modular enough to be statically linked, and also works fine as a shared library. It also includes an excellent UI builder called FLUID that can be used to create applications in minutes.