What software can I use to simulate I.B.I.S Models?
The unfortunate fact is that you need Mentor Graphics Hyperlynx, Cadence SigXplorer, Agilent ADS, Synopsys HSpice or a similar caliber software. 

I have looked high and low - tried many different ones - to find any free options for my courses in signal integrity. Unfortunately we are not quite there yet.

Altium can do some IBIS simulation as well, but last time I tried they were not really up to par.

If you have an interesting problem, feel free to put it up as a question and I may just quickly run it through SigXplorer or Hyperlynx for you (and add it to my blog or as an example in my courses).

Did that help?