The Sun Corporation (they that own the Java programs) have had a free equivalent version of the Office suite for quite a long time. It is called OpenOffice and is currently on version 3.3
Once you get 'inside' the Sun version of say Excel (it is called calc) then there is very little difference in how it is used & even the Functions often have the same name - and programming in either is very similar as the both use (slightly different) versions of Basic.
However OpenOffice rather let itself down on the ability to import raw data from other sources (text, pdf) directly into things like the Database package. Here Microsoft Office had a very strong edge.
OpenOffice has traditionally been a great favourite of the Linux community because it is open source & free. However in October of last year some members of the OpenOffice Project formed a new venture called The Document Foundation. They invited Sun to join this group however Sun were not best pleased with the whole concept. They refused to join & removed the members of the new organisation from their own project.
That group have now released their own rival to Microsoft Office called LibreOffice 3.3. It has picked up a major supplier of Linux operating system (Ubuntu) as a friend & they say they will issue it as the default office suite in their OS from now on. It is rumoured that the other suppliers of Linux will follow suit shortly.
Why the split away.. well, reading between the lines, I gather that the Oracle capture of Sun has not exactly been met with universal welcome by those dealing with OpenOffice. There is a feeling that Oracle's commercialism does not sit well with the open source environment that OpenOffice inhabits.
I have not tried LibreOffice yet (but I will be) however any reviews I have read would suggest that it is an improvement on the OpenOffice version 3.2 & as good as the new 3.3. Certainly some of the interface issues are claimed to have been removed.
It looks like the 2 projects will both carry on & develop. It will be interesting to see what the differences are in a couple of years. OpenOffice developed & improved largely because of its 'community' spirit & support groups which Sun managed to live comfortably with. It looks like Oracle will not find that such a happy marriage & I imagine that most of the 'free spirits' will desert to a new LibreOffice community.
For anyone interested in trying & using LibreOffice it can be downloaded for free here..
http://www.libreoffice.org/download/
To show no favouritism OpenOffice can be downloaded for free here..
http://download.openoffice.org/other.html#tested-full
For anyone interested in Microsoft Office, I can only say that you have more money than sense & you can pay for it where ever you like...
