GNU Recutils is a set of tools and libraries to access human-editable text-based databases called recfiles. A recfile contains data structured as a sequence of records. The rec format supports data integrity with the usage of record descriptors (keys, mandatory fields, field types, etc.) as well as the ability of record fields to refer to other records. Despite its simplicity, recfiles can be used to store medium-sized databases. The GNU recutils suite comprises a texinfo manual describing the Rec format, a C library (librec) providing a rich set of functions to access rec files, a set of C utilities that can be used in shell scripts and in the command line to operate on rec files, and an Emacs mode (rec-mode).
KDE-Services extends the features of the Dolphin File Manager right-click menu in the KDE graphical environment. It allows you to play and convert between several video formats, extract audio from movies and convert them to MP3 or FLAC, convert audio to MP3 or FLAC, securely send a file or directory to Mailx as an email, send files to Thunderbird as attachments, burn and checksum ISO images, execute scripts and applications, get low-level information on video files, build ISO images from folders, replace text, search, SSH, use Midnight Commander, use system, network, and backup/restore tools, use Samba, extract subtitles from MKV video, multiplex subtitles into MPEG-2 videos, and work with YouTube, DVDs, multimedia, GPG. You can add a timestamp prefix to a filename or directory name. A paranoid shredder, an HTTP publisher, graphic tools, RPM package tools, Xorg configuration, and Dropbox tools are included.
The minfx project is a Python package for numerical optimization. It provides a large collection of standard minimization algorithms, including the line search methods (steepest descent, back-and-forth coordinate descent, quasi-Newton BFGS, Newton, and Newton-CG), the trust-region methods (Cauchy point, dogleg, CG-Steihaug, and exact trust region), the conjugate gradient methods (Fletcher-Reeves, Polak-Ribiere, Polak-Ribiere +, and Hestenes-Stiefel), the miscellaneous methods (Grid search, Simplex, and Levenberg-Marquardt), and the augmented function constraint algorithms (logarithmic barrier and method of multipliers).
The GNU Autoconf Archive is a collection of more than 450 macros for GNU Autoconf. They can be re-used without imposing any restrictions on the licensing of the generated configure script. In particular, it is possible to use them in configure scripts that are meant for non-free software.
The OATH Toolkit makes it easy to build one-time password authentication systems. It contains shared libraries, commandline tools, and a PAM module. Supported technologies include the event-based HOTP algorithm (RFC4226) and the time-based TOTP algorithm (RFC6238). OATH stands for Open AuTHentication, which is the organization which specifies the algorithms. For managing secret key files, the Portable Symmetric Key Container (PSKC) format described in RFC6030 is supported.
GCC-MELT is a high-level domain specific language that eases the development of plugin-like extensions for GCC, the Gnu Compiler Collection. These extensions can analyze or modify GCC internal representations, and can be used for static source code analysis, refactoring, specific warnings, optimizations, etc. The MELT language provides high-level features. Notably, MELT code is translated to C or C++, and can even contain C or C++ code. It includes powerful pattern matching facilities and can manipulate dynamically typed values and raw GCC structures. It enables functional/applicative, object-oriented, reflective programming styles and has a familiar Lisp-like syntax.
CGAL, the Computational Geometry Algorithms Library, is a large C++ library of geometric data structures and algorithms such as Delaunay triangulations, mesh generation, Boolean operations on polygons, and various geometry processing algorithms. CGAL is used in various areas: computer graphics, scientific visualization, computer aided design and modeling, geographic information systems, molecular biology, medical imaging, robotics and motion planning, and numerical methods.