Can you please give me a couple of examples?
All of the major tool vendors do limited time evaluations and probably some of the lesser known also. Look at the vendor sites and see what is available.
Click on some of the tools advertisements on QAforums - they will lead you to the right places.
I have not failed. I've just found 10,000 ways that won't work" --Thomas Edison
I am wondering whether there is trial version of any automation tool out there for load testing web application?
Yes, there are plenty of trial versions.
Joe StrazzereVisit my website: AllThingsQuality.com to learn more about quality, testing, and QA!