Chapter 5. Software available in the Debian system

Like most Linux distributions, Debian GNU/Linux provides:

More than 58100 packages, ranging from news servers and readers to sound support, FAX programs, database and spreadsheet programs, image processing programs, communications, net, and mail utilities, Web servers, and even ham-radio programs are included in the distribution. Other 1000 software suites are available as Debian packages, but are not formally part of Debian due to license restrictions.

For each package the authors of the program(s) are credited in the file /usr/share/doc/PACKAGE/copyright, where PACKAGE is to be substituted with the package's name.

Maintainers who package this software for the Debian GNU/Linux system are listed in the Debian control file (see Section 7.4, “What is a Debian control file?”) that comes with each package. The Debian changelog, in /usr/share/doc/PACKAGE/changelog.Debian.gz, mentions the people who've worked on the Debian packaging too.

A complete list is available from any of the Debian mirrors, in the file indices/Maintainers. That file includes the package names and the names and e-mails of their respective maintainers.

The WWW interface to the Debian packages conveniently summarizes the packages in each of about thirty "sections" of the Debian archive.

If you want to build packages in your Debian system you will need to have a basic development environment, including a C/C++ compiler and some other essential packages. In order to install this environment you just need to install the build-essential package. This is a meta-package or place-holder package which depends on the standard development tools one needs to build a Debian package.

Some software can, however, need additional software to be rebuilt, including library headers or additional tools such as autoconf or gettext. Debian provides many of the tools needed to build other software as Debian packages.

Finding which software is precisely required can be tricky, however, unless you are planning on rebuilding Debian packages. This last task is rather easy to do, as official packages have to include a list of the additional software (besides the packages in build-essential) needed to build the package, this is known as Build-Dependencies. To install all the packages needed to build a given source package and then build said source package you can just run:

# apt-get build-dep foo
# apt-get source --build foo

Notice that if you want to build the Linux kernels distributed by Debian you will want to install also the kernel-package package. For more information see Section 10.2, “What tools does Debian provide to build custom kernels?”.

There is a list of packages which still need to be packaged for Debian, the Work-Needing and Prospective Packages list.

For more details about adding missing things, see Chapter 13, Contributing to the Debian Project.

Debian Policy requires that such symbolic links (to libfoo.so.x.y.z or similar) are placed in separate, development packages. Those packages are usually named libfoo-dev or libfooX-dev (presuming the library package is named libfooX, and X is a whole number).

Several free implementations of Java technology are available as Debian packages, providing both Java Development Kits as well as Runtime Environments. You can write, debug and run Java programs using Debian.

Running a Java applet requires a web browser with the capability to recognize and execute it. Several web browsers available in Debian, such as Mozilla or Konqueror, support Java plug-ins that enable running Java applets within them.

Please refer to the Debian Java FAQ for more information.

In order to make sure that your system has been installed from the real Debian base disks, use the

lsb_release -a

command. It will display the name of the distribution (in Distributor ID field) and the version of the system (in Release and Codename fields). The following is an example run in a Debian system:

$ lsb_release -a
No LSB modules are available.
Distributor ID: Debian
Description:    Debian GNU/Linux 7.4 (wheezy)
Release:    7.4
Codename:   wheezy

You can also check for the existence of /etc/debian_version file, which contains a single one-line entry giving the version number of the release, as defined by the package base-files.

Users should be aware, however, that the Debian system consists of many parts, each of which can be updated (almost) independently. Each Debian "release" contains well defined and unchanging contents. Updates are separately available. For a one-line description of the installation status of package foo, use the command dpkg --list foo. For a more verbose description, use:

dpkg --status foo

To view versions of all installed packages, run:

dpkg -l

Note that the existence of the program dpkg shows that you should be able to install Debian packages on your system. However, since the program has been ported to many other operating systems and architectures, this is no longer a reliable method of determining if a system is Debian GNU/Linux.

Dan J. Bernstein used to distribute all software he has written with a restrictive license which does not allow modified binaries to be distributed. In november 2007 however, Bernstein said "[...] i have decided to put all of my future and [...] past software into the public domain". See FAQ from distributors for his distribution terms.

As of this writing (2016-03), ezmlm-idx is available in experimental only (mlmmj is similar, and shipped with Debian jessie); djbdns is available in sid (unstable) only, see Bug #516394 and Bug #796118 for details and see dbndns for a similar alternative; the publicfile software is still not free software, a publicfile-installer package is available from Debian's contrib section.

Other software of Dan J. Bernstein (qmail, daemontools, ucspi-tcp) is shipped with Debian.

Debian ships both gnash and swfdec: two free SWF movie players.

Google Earth is available for GNU/Linux from Google's web site, but not only it is not Free Software, but is completely undistributable by a third party. However, googleearth-package (in the contrib-section) might be helpful in using this software.

Two main open protocols are used for Voice Over IP: SIP and H.323. Both are implemented by a wide variety of software in Debian main. ekiga is one of the popular clients.

Buy one which does :)

Alternatively, use ndiswrapper to use a driver for Windows (if you have one) on your Linux system. See the Debian Wiki ndiswrapper page for more information.