Browsing Belarusian translation

19.

To organise the software, Xubuntu repositories are categorised into four groups: <emphasis>Main</emphasis>, <emphasis>Restricted</emphasis>, <emphasis>Universe</emphasis>, and <emphasis>Multiverse</emphasis>. The rationale used to determine which software goes into which category is based on the level of support that software development teams provide for a program and the level of compliance the program has to the <ulink url="http://www.ubuntu.com/ubuntu/philosophy">Free Software Philosophy</ulink>.

20.

The standard Xubuntu Install CD contains some software from the <emphasis>Main</emphasis> and <emphasis>Restricted</emphasis> categories.

29.

Enter the <guilabel>APT line</guilabel> for the extra repository. This should be available from the website of the repository or similar, and should look similar to the following:

33.

Most software repositories use a GPG key to digitally sign the files they provide, which makes it easy to check that the files have not been tampered with since their creation. In order for apt to be able to check this, you need the public key that corresponds to the signatures. The key should be available for download on the repository's website.

34.

Once you have downloaded the GPG key, import the key by selecting the <guilabel>Authentication</guilabel> tab, clicking on <guibutton>Import Key File</guibutton>, and then selecting the GPG key to be imported.

37.

If you click <menuchoice><guimenu>Applications</guimenu><guisubmenu>System</guisubmenu><guimenuitem>Software Sources</guimenuitem></menuchoice> and select the <guilabel>Updates</guilabel> tab, you will notice that four update sources are available. An explanation for each of these is provided below:

38.

<emphasis role="strong">Important security updates:</emphasis> Updates which fix critical security flaws are made available through this source. It is recommended that all users leave this source enabled (it should be enabled by default).

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.