LibreOffice is community-driven and developed software, and is a project of the not-for-profit organization, The Document Foundation. It is developed by users who, just like you, believe in the principles of Free Software and in sharing their work with the world in non-restrictive ways. At the core of these principles are the four essential freedoms and the tenets of The Document Foundation’s Next Decade Manifesto. LibreOffice is a freely available, fully-featured office productivity suite. Its native file format is Open Document Format (ODF), an open standard format that is being adopted by governments worldwide as a required file format for publishing and accepting documents. LibreOffice can also open and save documents in many other formats, including those used by several versions of Microsoft Office. For more information you can visit the Libre Office Information page.
1.) Update Your System.
It is important to first make sure that your machine is fully updated before installing any new software. Open up the Terminal (CTRL+ALT+t) and use this command to update and upgrade your system.
$ sudo apt-get update && sudo apt-get upgrade
2.) Add PPA.
Now that your system is up to date you can begin the process of adding the repository for Libre Office.
$ sudo add-apt-repository ppa:libreoffice/ppa
3.) Review Details.
You will see a description of the repository along with other information. Press Enter to continue.
4.) Update Sources.
Now you need to update your source list for the repository you just added.
$ sudo apt-get update