Xubuntu is built from this type of software. This software is free for anyone to install and use, and people can modify the software and redistribute it if they like. Most of the software available for Xubuntu is free, open-source software. Once you have downloaded the GPG key, import the key by selecting the Authentication tab, clicking on Import Key File, and then selecting the GPG key to be imported. The key should be available for download on the repository's website. In order for apt to be able to check this, you need the public key that corresponds to the signatures. 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.
You will be notified that the information about available software is out-of-date. Press Add Source and then click Close to save your changes. This is available from the website of the repository in the majority of cases and it should look something like the following: deb etch main Open → Settings Manager → Software & Updates or → Software → Software & Updates and go to the Other Software tabĮnter the APT line for the extra repository.
