Open office is an open source office software suite word processing, spreadsheets, presentations etc. It is intended to be an open source substitute to Microsoft Office.
Although it is not as sophisticated a MS Office, it has almost all the features of any other software package and it is very easy to use. And did I mention its free!!!
You are free to download it from here completely free of charge and use it for any purpose.
Open Office also has a lot of extensions that can be added to it to increase and improve its functionality. Click here to see a complete list of these extensions
Open Office 
Open office is an open source office software suite word processing, spreadsheets, presentations etc. It is intended to be an open source substitute to Microsoft Office.
