Xin,
From my experience, I dont think you cant get the Full Software Version for Free. But, you can always make use of the Evaluation Software that should be free for 30 days or so.
For example:
http://www.rsasecurity.com/node.asp?id=1080
Your best bet is to go to www.rsasecurity.com and look up the product(s) you want to test and then look for free trial offers.
Let me know it it helps.
Regards,
Arul