I’m not sure if you are talking about commercial scripts like the ones from VASST and JetDV or free scripts that people write. Theo has shown you the list from JetDV. At VASST we list the compatible versions on the product page. Basically all of our latest products (Ultimate S Pro/Lite, GearShift, infinitiCAM, Celluloid, GrafPaks, ReelPaks, etc.) have been updated to work from Vegas 6 through Vegas Pro 9.0 64-bit.
As for free scripts, there is no way of knowing. Sony changed the script API several times even making some functions behave differently from version to version so you never know what you’re getting unless the original script author went back and fixed the script to compensate for these changes. You just need to contact the various authors if they were kind enough to place their email in the comments of the script file. That’s why it pays to buy commercial scripts that are tested and maintained (buy you would expect me to say that since I write the scripts for VASST). 😉
~jr
http://www.johnrofrano.com
http://www.vasst.com