R is one of those hidden but very useful open source tools.
While the SAS products are good, dealing with SAS as an organisation is like dealing with a cult. They refuse to allow third-parties OEM their products, insult and demean their partner base and charge a fortune for their products.
After spending money on the initial licence, they charge around 40% of the licence fee annually or their products stop working.
Because they had not real competition, they had had no reasons to change their behaviour.
There is a real business now in targetting SAS users with a valid alternative.
The world of data analysis and mining is really changing with tools and standards like PPML from the Data Mining Group, open source Rapid Miner, R as well as the more obscure such as Cassandra.