Previous article in, I introduced the free OpenOffice.org as Microsoft Office alternative is an expensive software.
Another option, Google Docs is also thing. Here because the WEB interface of the use anywhere not even need installation, I think that it is great to have been evolving function. Recently, I'd like now presentation document (corresponding to MS-Office of PowerPoint) can use.
Just to inferior still to MS-Office and OpenOffice as a function, and to seems not use scripts (macros) also because no match for ordinary application in the operability even luck How much is now the technology because WEB interface There is status quo.
In the future, I think there is a possibility that Google Docs is replace the MS-Office and OpenOffice, but it'd still be ahead of things.
I found an interesting article below. Share of office applications, Microsoft Office is 51%, OpenOffice.org is 5%, GoogleDocs is seems to 1%. It is where reasonable.
OpenOffice five times more popular than Google Docs