Asterisk is a hybrid TDM and packet voice PBX (Private Branch eXchange) and IVR platform with ACD functionality. It acts as middleware between the Internet (IAX, SIP, MGCP, Skinny, H.323), telephony channels (like Zaptel, T1, PRI, E1, FXO, FXS, VoIP, VoFR, ISDN, modems, Internet Phone Jack, etc.), and applications (like voice-mail, conferencing, directories, MP3 players, intercoms, etc.). It has many advanced features such as a codec translation API. The base distribution includes several channel backends, as well as applications. However, the beauty of Asterisk is its ability to be extended using its APIs, dynamic module loader, and AGI scripting interface. End users can even write their own applications that run on the system in C or any scripting language of their choice.
Tcl provides a portable scripting environment for Unix, Windows, and Macintosh that supports string processing and pattern matching, native file system access, shell-like control over other programs, TCP/IP networking, timers, and event-driven I/O. Tcl has traditional programming constructs like variables, loops, procedures, namespaces, error handling, script packages, and dynamic loading of DLLs. Tk provides portable GUIs on UNIX, Windows, and Macintosh. A powerful widget set and the concise scripting interface to Tk make it a breeze to develop sophisticated user interfaces.
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 For most purposes, however, it is superseded by full-screen editors such as GNU Emacs or GNU Moe.
pngcrush is an excellent batch-mode compression utility for PNG images. Depending on the application that created the original PNGs, it can improve the file size anywhere from a few percent to 40% or more (completely losslessly). The utility also allows specified PNG chunks (e.g. text comments) to be inserted or deleted, and it can fix incorrect gamma info written by Photoshop 5.0 as well as the erroneous iCCP chunk written by Photoshop 5.5.
CDfs is a file system for Linux systems that `exports' all tracks and boot images on a CD as normal files. These files can then be mounted (e.g. for ISO and boot images), copied, played (audio tracks), etc. The primary goal for developing this file system was to `unlock' information in old ISO sessions. The file system also allows you to access data on faulty multi session disks, e.g. disks with multiple single sessions instead of a multi session.
Seed7 is a general purpose programming language. It is a higher level language compared to Ada, C++, and Java. In Seed7, new statements and operators can be declared easily. Functions with type results and type parameters are more elegant than a template or generics concept. Object orientation is used when it brings advantages and not in places when other solutions are more obvious. Although Seed7 contains several concepts of other programming languages, it is generally not considered as a direct descendant of any other programming language.
Sylpheed is a simple, lightweight but featureful, and easy-to-use email client. It has a well-polished and comfortable user interface. It has many features such as multiple accounts, thread display, MIME, powerful filtering, various search interface, spell checking, and junk mail control. It supports common email protocols such as POP3, IMAP4rev1, SMTP, and security features such as GnuPG and SSL/TLSv1. It is also fully internationalized and multilingualized.
Lynx is a fully-featured WWW client for users running cursor-addressable, character-cell display devices (e.g., vt100 terminals, terminal emulators running on PCs or Macs, or any other character-cell display). It will display HTML documents containing links to files on the local system, as well as files on remote systems running HTTP, HTTPS, gopher, FTP, WAIS, NNTP, finger, or cso/ph/qi servers, and services accessible via logins to telnet, tn3270, or rlogin accounts.
UnZip will list, test, or extract files from a ZIP archive, commonly found on DOS and Windows systems. A companion program, Zip, creates ZIP archives; both are part of the Info-ZIP project. Both programs are compatible with archives created by PKWARE's PKZIP or Nico Mak's WinZip, but in many cases the program options or default behaviors differ.