You may already have heard of the GNU Project, and you may vaguely remember reading various notices referencing the GNU and the GPL in software you use regularly. But do you really know what the GNU Project does, or how extensive an impact its software has on your daily life?

The GNU Project (the name's an acronym which stands for "GNU's Not Unix") creates sophisticated, user-friendly software that users may freely use, modify, redistribute, even sell. This license is called the General Public License, or GPL. GNU/GPL software is commonly used in combination with the open-source Linux kernel to create the free, open-source GNU/Linux operating system, and most major Linux distros use GNU software.

In this article, we introduce you to 10 GNU/GPL programs you can't do without if your operating system of choice is UNIX-based. Six of these are developed by the GNU Project and licensed under the GPL; the remaining four are developed by third-party projects and licensed under terms similar (but not identical) to the GPL.

Program

Description

Features

License

Bash

A sophisticated command shell that can be used for launching programs or scripting tasks in the GNU environment.
  • POSIX compliance
  • Command-line completion
  • Job control
  • Compatibility with sh shell scripts

GNU General Public License

GNOME

A powerful, easy to use graphical desktop environment for the X-Windows system.
  • A complete desktop environment for *NIX, with multimedia, Web browsing, office applications and system maintenance tools
  • Compatibility with Windows files
  • Available in multiple languages
  • Includes support for handicapped users

GNU General Public License

GnuPG

A tool to protect individual privacy by encrypting files and email messages using unbreakable cryptographic algorithms.

  • OpenPGP compliance
  • Supports wide variety of encryption routines, including Blowfish, DSA, RSA, SHA-1 and El-Jamal
  • Supports key retrieval from online key servers

GNU General Public License

GZip

A utility that enables more efficient data storage by compressing files, thereby saving space and making file transfers easier.
  • Offers better/faster compression than zip/unzip

GNU General Public License

GCC

A developer toolkit containing a powerful C compiler and associated tools.
  • ANSI C compliant
  • Supports C, C++, Objective-C, Fortran, Java, and Ada

GNU General Public License

Samba

A suite of tools to improve interoperability between Windows and *NIX systems, by making file and printer sharing possible between them.
  • Can access local or network Windows shares through *NIX
  • SMB- and CIFS compliance
  • Supports Windows trust accounts, domain/network logon and user/share level security
  • Includes Web-based configuration tool

GNU General Public License

Sendmail

A sophisticated mail transfer agent that accepts mail and delivers it to the remote host.
  • Mail filtering
  • On-the-fly address rewriting
  • Anti-spam features

Sendmail License

Vim

The de facto *NIX text editor, suitable for editing a variety of ASCII file formats.
  • Multi-byte text support
  • Automatic text completion
  • Command history buffer
  • Macro support
  • Built-in scripting language
  • Data recovery features
  • Syntax highlighting

Vim License

Apache

A standards-compliant Web server used by a majority of Internet Web sites.
  • HTTP 1.1 compliance
  • Plug-in architecture for external modules (DSO)
  • Supports CGI, SSI and HTTP-Authentication
  • Can host multiple virtual hosts on the same system

Apache License

OpenSSH

A suite of remote access tools that improve network security by encrypting communications between hosts.
  • Encrypts all traffic between hosts, including passwords
  • Provides secure alternatives to telnet, ftp and rcp
  • Supports creation of secure "tunnels" between hosts
  • Can use both public key and one-time password authentication
  • Supports 3DES, Blowfish and AES encryption

BSD License