Browsing Icelandic translation

39.

<emphasis role="strong">Recommended updates:</emphasis> Updates which fix serious software problems (which are not security flaws) are made available through this source. Most users will want to leave this source enabled as common and annoying problems are often fixed with these updates.

40.

<emphasis role="strong">Pre-released updates:</emphasis> Updates which are currently being tested before being released to everyone are provided through this update source. If you would like to help test new updates (and get fixes for problems more quickly), enable this source. Be aware that these updates may not yet be well tested; it is not recommended that you enable this source unless you are prepared to experience occasional problems.

41.

<emphasis role="strong">Unsupported updates:</emphasis> When new versions of popular software are released they are sometimes <quote>back-ported</quote> to an older version of Xubuntu so that users can benefit from new features and fixes for problems. These backports are unsupported, may cause problems when installed and should only be used by people who are in desperate need of a new version of a software package which they know has been backported.

42.

Restricted and non-free software

43.

Most of the software available for Xubuntu is free, open-source software. This software is free for anyone to install and use, and people can modify the software and redistribute it if they like. Xubuntu is built from this type of software.

44.

<emphasis role="strong">Non-free software</emphasis> is software which is not freely redistributable or modifiable. This makes it difficult for the Xubuntu developers to improve the software and correct problems, so it is normally recommended that you use <ulink url="http://www.ubuntu.com/ubuntu/philosophy"> free software</ulink> instead.

45.

<emphasis role="strong">Restricted software</emphasis> is software which has restrictions on its use, preventing it from being classed as free software. Non-free software is a type of restricted software, where the restrictions are due to the software having a non-free license. Other reasons for software being classed as restricted include legal issues (use of some types of software is illegal in some countries) and patent issues (some software requires a patent license to be used legally).

46.

In some cases, restricted software is the only option. Such cases include software for the playback of certain audio and video formats, some fonts and <link linkend="restricted-manager"><application>drivers for some graphics cards</application></link>.

47.

You should be warned by the package manager when you try to install restricted software. If the restricted software cannot be used legally in your country then there is little you can do; you should not install the software. If the software is restricted simply because it is non-free, you may choose to use it (for example, in the case of graphics card drivers). Be aware that most restricted software is not supported in Xubuntu, and problems with such software often cannot be corrected by Xubuntu developers.

48.

Sometimes it is difficult to determine why a particular software package is restricted. If this is the case, seek advice on the <ulink url="http://ubuntuforums.org/">Ubuntu Forums</ulink>. If you are still unable to determine why a package is restricted, err on the side of caution and do not install it; it may be illegal to use it in your country.