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.
Allegro is a multi-platform game library for C/C++ developers that provides many functions for graphics, sounds, player input (keyboard, mouse, and joystick), and timers. It also provides fixed and floating point mathematical functions, 3D functions, file management functions, compressed datafile, and a GUI.
asmutils is a set of miscellaneous utilities written in assembly language, targeted on embedded systems and small distributions (e.g. installation or rescue disks). It also contains a small libc and a crypto library. It is optimized for size, memory usage, and speed, and offers fairly good functionality. The project supports Linux and the BSD family. Unixware, Solaris, and AtheOS support is in beta stage. This package also aims to provide a portable development framework, and to encourage assembly programmers to write for Linux/Unix.
curl and libcurl is a tool for transferring files using URL syntax. It supports HTTP, HTTPS, FTP, FTPS, SCP, SFTP, TFTP, DICT, TELNET, LDAP, POP3, IMAP, SMTP, RTSP, RTMP, and FILE, as well as HTTP-post, HTTP-put, cookies, FTP upload, resumed transfers, passwords, port numbers, SSL certificates, Kerberos, and proxies. It is powered by libcurl, the client-side URL transfer library. There are bindings to libcurl for about 40 languages and environments.
getmail is intended as a simple, secure, and reliable replacement for fetchmail. It retrieves email (either all messages, or only unread messages) from one or more POP3, SPDS, or IMAP4 servers (with or without SSL) for one or more email accounts, and reliably delivers into qmail-style Maildirs, mboxrd files, or through external MDAs (command deliveries) specified on a per-account basis. getmail also has excellent support for domain (multidrop) mailboxes, including delivering messages to different users or destinations based on the envelope recipient address.
ICI is a general purpose interpretive programming language that has dynamic typing and flexible data types with the flow control constructs and operators of C. It is designed for use in many environments, including embedded systems, as an adjunct to other programs, as a text-based interface to compiled libraries, and as a cross-platform scripting language with good string-handling capabilities.
interpcom is a command interpreter library in C that can be used to build scientific applications. It is very easy to add new commands. The library contains an expression evaluator that can be used to parse the arguments of the commands. It is possible to define "objects" which are arrays of numbers having a name, and structures. It is possible to use threads (several programs running simultaneously).