Open Office () is open source software, collaboratively developed by people from all over the world. The Microsoft Office Suite (MsOffice), on the other hand, was solely developed by the Microsoft Corporation. They have pretty much the same content - a word processor, a spreadsheet application, a presentation maker, etc. However, they have some major differences that makes them unique from each other.
First - Open Office is cheaper than MsOffice. The cheapest MsOffice package starts at USD 149.99 while Open Office is absolutely free. A hundred and fifty dollars may not hurt a lot, but this becomes a considerable pain in the neck when a large company has a lot of computers to install it to, as the each MsOffice package can be installed on just one computer, as required by law.
Many universities across the world have shifted to OpenOffice because of this. The University of Melbourne and the US State of Maine are just two of them. Various private companies have also adopted them, such as Sumitomo of Japan, and also government offices, like the City Government of Berlin, Germany.
However, some institutions still prefer MsOffice due to its popularity and familiarity. Some features of OpenOffice work in a very odd and unintuitive way. For example, putting page numbers on text files in OpenOffice Writer can be one heck of a challenge, while it takes only a couple of seconds in Ms Word.
Second - OpenOffice has everything in it, unlike some MS Office Packages. All of the features of OpenOffice are already there - it has an equation editor, an HTML editor, everything. On the other hard, the basic MsOffice package, MsOffice Student Edition at USD 149.99, only has Excel (spreadsheet), Word (word processor) and PowerPoint (presentation maker), while everything else is a la carte. A full MsOffice package can cost as much as USD 499.99 - the same price for a mid-end laptop.
However, MsOffice gives more comprehensive technical support than its competitor. MsOffice offers phone-based support, something that is very important for someone who needs accurate answers fast. OpenOffice on the other hand, offers only forum-based support, which can be problematic especially when you do not know the name for the feature that you are having a problem about.