ONLYOFFICE Desktop Editors is a free and open source office suite that allows users to edit text documents, spreadsheets and presentations offline by providing access to the web-based ONLYOFFICE portals for an efficient remote team collaboration.
What's new in ONLYOFFICE Desktop Editors 4.2 Opening and editing footnotes. Inserting equations into a worksheet or a presentation. Using sparkline charts for a trend analyze. New visual chart styles. 3D diagrams rotation. System requirements CPU: dual-core 2 GHz or better. RAM: 2 GB or more. HDD: at least 2 GB of free space. Installing and running ONLYOFFICE Desktop EditorsAdd GPG key:
sudo apt-key adv --keyserver hkp://keyserver.ubuntu.com:80 --recv-keys CB2DE8E5
Open the /etc/apt/sources.list file using any available text editor:
sudo nano /etc/apt/sources.list
Add the following record to add the desktop editor repository:
deb http://download.onlyoffice.com/repo/debian squeeze mainUpdate the package manager cache in order to use the created repository:
sudo apt-get update
Install ONLYOFFICE Desktop Editors:
sudo apt-get install onlyoffice-desktopeditors
Run ONLYOFFICE Desktop Editors:
desktopeditors

Connecting ONLYOFFICE Desktop Editors to a web office
Select the Share&Collaborate option on the left-side panel:

Click the Connect link at the bottom:

Enter your portal name, the email, and password you use to access it and click the Login button:

That's all. You have a desktop access to your documents stored in the web office and can edit and collaborate on them without browser limitations.