I recently came across Kendo UI Web, and I was pretty impressed, but I have a question about their licencing. The web version is licensed under the GNU/GPL, which if my understanding is correct, means that I can use it for free as long as I too abide by the GPL. In this case, if I'm using it as a JavaScript library, and I don't modify it, and I use it as part of a commercial product, there should be nothing wrong with that, and unless I need or want support, I legally do not have to pay them. I tried emailing them, and they just referred me to a forum post (which did not answer my question). Does anyone have any experience with this?