I'm not sure this is a support issue or not, but I'll put it here as I'm not sure which heading to put it under.
I tried to use Gravityforms on my local machine with XAMPP where I do my testing and working out the bugs. I got an error when I tried to activate it.
I used the same .zip file to upload to my remote site and no problems.
Anyone else found this, it's not a deal breaker, but it would be nice to be able to use it with XAMPP.