IBIS models simulator

Hi everyone, 

I am not sure if my post is in the right place. Anyhow I just downloaded Xilinx and Altera IBIS models. The Altera model is just a word file while Xilinx is a file with an extension .ibs . So is there a specific simulator to run these models or I can use quartus and xilinx simulators to simulate them?
Also can I simulate the model using PSPICE because I tried but didn't know how to import the file to PSPICE and run it ? Should I convert the file first?

Thanks