Microsoft Office is one of the most popular and widespread office suites for everyday tasks. Most companies install it on their employees' computers and this enables them to open documents, work on spreadsheets or view a presentation in a comfortable way, all from the same software package.
Now what if you don't have Office installed, for example, in your home computer? You probably can't afford the license or simply don't want to install the whole thing just for viewing the odd fun Powerpoint presentation your friends email you. The perfect solution for these situations is the Microsoft official viewers for Word, Excel and Powerpoint files.
These small, simple apps enable you to open DOC, XLS, PPT and other file formats that are usually managed by the Office suite, so that you can view Office documents without actually having the Microsoft Office suite installed on your system. These viewers work with all Office versions from 97 to 2003, but you may need to install a special Compatibility Pack to open the DOCX format from Word 2007.
Bear in mind that these tools are intended just for viewing files, meaning you won't be able to edit them. In any case, it's a handy way to open Office files when you don't have the original Office apps.