You might ask on the DUC (Digi User Conference) at digidesign.com.
It's going to depend if you are MAC or PC based as to what is available for you and if you are running real ProTools or ProTools LE. ProTools Free is a sub set of LE, AFAIK.
Real ProTools runs card based plug ins and I believe, RTAS (Real Time Audio Suite) and maybe AS (Audio Suite). PTLE runs RTAS and AS.
If you are looking for free. Consider systems that make use of Direct-X plug ins.
' hope this helps.