GNU ed is an 8-bit clean implementation of the POSIX line-oriented text editor. Ed is the "standard" text editor in the sense that it is the original editor for Unix, and thus widely available. For most purposes, however, it is superseded by full-screen editors such as GNU Emacs or GNU Moe.
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.
GNU ddrescue is a data recovery tool. It copies data from one file or block device (hard disk, CD-ROM, etc.) to another, trying to rescue the good parts first in case of read errors. GNU ddrescuelog is a tool that manipulates ddrescue logfiles, shows logfile contents, converts logfiles to/from other formats, compares logfiles, tests rescue status, and can delete a logfile if the rescue is done.
GNU Moe is a powerful, 8-bit clean console text editor for ISO-8859 and ASCII character encodings. It has a modeless, user-friendly interface, online help, multiple windows, unlimited undo/redo capability, unlimited line length, global search/replace (on all buffers at once), block operations, automatic indentation, word wrapping, filename completion, a directory browser, duplicate removal from prompt histories, and delimiter matching.
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.
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 fstrcmp library provides an fstrcmp function that returns a number between 0.0 (nothing alike) and 1.0 (identical); this can be used to suggest likely alternatives in error messages. Fuzzy comparisons for byte arrays, wide character strings, and multi-byte character strings are also available. In addition, there are integer alternatives for systems with slow floating point emulation.
dxirc is a easy-to-use yet capable cross-platform IRC client. Among its notable features are flexible configuration, a fully customizable look independent of system-wide settings, multiple server support with optional automated joining of selected channels, and the ability to connect via SSL.