Ghostscript is a processor for PostScript and PDF files. It can rasterize these files to a wide variety of printers, devices for screen preview, and image file formats. Since applications tend to prepare pages for printing in a high-level format such as PostScript, most Unix users with low-level bitmap printers, such as inkjets, use GhostScript as part of the printing process. In addition, Ghostscript is capable of converting PostScript files, functionality comparable to Adobe Acrobat Distiller, but on the command line. In addition, Ghostscript is used for file import and viewing by a great many other applications, including xv, ImageMagick, gimp, and xdvi. Several GUI wrappers for viewing PostScript and PDF files exist, including GSview, ghostview, gv, ggv, and kghostview. This is far from a comprehensive list.
MUSCLE (Multi User Server Client Linking Environment) is an N-way messaging server and networking API. It includes client-side networking APIs for various languages, including C, C++, C#, Delphi, Java, and Python. MUSCLE lets programs communicate over a network via streams of serialized Message objects. The included server program ("muscled") lets its clients message each other and store information in its server-side hierarchical database. The database supports flexible queries via hierarchical wildcarding, and "live" updates via a subscription mechanism.
The Extended Module Player is a command-line mod player for Unix-like systems that plays over 90 mainstream and obscure module formats from Amiga, Atari, Acorn, Apple IIgs, C64, and PC, including Protracker (MOD), Scream Tracker 3 (S3M), Fast Tracker II (XM), and Impulse Tracker (IT) files.
VLC media player is a multimedia player, framework, streamer, and encoder. It can play inputs like files, network streams, DVDs, audio CDs, Blu-Rays, capture devices, and screens. It can play most audio and video codecs and formats (MPEG 1/2/4, H264, VC-1, DivX, WMV, Vorbis, AC3, AAC, MKV, etc.), but can also be used to convert to different formats and/or send streams through the network.
The ATLAS (Automatically Tuned Linear Algebra Software) project is an ongoing research effort focusing on applying empirical techniques in order to provide portable performance. It provides C and Fortran77 interfaces to a portably efficient BLAS implementation, as well as a few routines from LAPACK.
Njam is a full-featured cross-platform Pacman-like game that uses the SDL library. It features single and multiplayer modes (local or network), duel games where players compete against each other to get more points, cooperative games where players cooperate to finish as many levels as they can, and great music and sound effects. It includes customizable level skin, many different levels, and an integrated level editor.
smake is a highly portable 'make' program that makes commands up to date based on rules in Makefiles and on the timestamps of the related files. It implements a complete superset of the features of the classical POSIX/Unix make program. It warns about typical misuse of dynamic macros that prevent portability of makefiles. Its automake features allow you to run scripts to automatically create rules for unknown platforms.
FFmpeg is a tool for converting audio, video, and subtitles. It includes libavcodec, the leading open source codec library. It also includes libavformat (implementing muxers and demuxers), libswscale (for very fast video scaling), and libavfilter (an advanced video filter system supporting arbitrary filter graphs), and libavutil (a utility library intended to supplement libc). A simple multimedia player is included too. An experimental streaming server for live broadcasts is also included.
FrobTADS is a complete rewrite of the Unix console-version of TADS ("Text Adventure Development System"). It uses curses (or ncurses) and provides an interpreter to play games developed with TADS as well as the TADS 2 and 3 development tools. It adds support for a number of relatively recent user interface features including full support for text and background colors, TADS 3 banner windows, and timed input. It's also much more portable and more easily maintainable, as it's built to modern Unix standards.