Microsoft Sharepoint


Does anybody know how I can install Micrsoft Sharepoint onto my domain? Is the setup easy? Is it possible?

I dont know if one has to sign up for a sharepoint service provider such as APPTIX or
However, its rather expensive at $20 per month, for a not-for-profit organization to afford.

Is there any other program, perhaps at that provides similar capabilities? I would prefer to have sharepoint though because of the amazing interface.