The company I work for is constantly increasing our workforce & with that is the need for more computers & with the need for more computers comes the need to license the software on those computers (unless you're the type that thinks it is ethical to hack everything). 

This can quickly become expensive so our IT department came up with an alternative.  OpenOffice is a freeware system comparable to Microsoft's Office package (Excel, Word, Access...).

As our office's unofficial Excel guru it is my job to help implement this portion of the package.  At first I didn't think too highly of the package but now I've even downloaded it on my home computer & more than likely will remove my old Microsoft package.

There are some minor quirk differences between Excel & Calc (OpenOffice's name for their version) but for the most part a user will find OpenOffice's package to be an easy transition.

I use formulas alot & I did notice some of the syntax is dramatically different (such as needing to use ; instead of , in a conditional statement) but it converts fine between the two systems.  Yes, you can save your work as an Excel extension.

What I like most though is that Microsoft just decided to dramaticly change the Excel & MSWord interface from the basic interface they had been using for over a decade -- who told them to do that???   -- anyhow the OpenOffice version retains the familiar interface  -- YAY!

So, if you use either MSWord or Excel (or other parts of the MSOffice package), you might want to look into OpenOffice.  Go to OpenOffice.org & check it out where you can download the latest FULL version absolutely FREE!