I like the jQuery Isotope plugin and I want to use it on my website. I was wondering if it was OK to use it without a licence.
It's licensed under either GPLv3 as an open-source license, or there's a commercial license available if you want to keep your code proprietary.
I am not gonna sell the plugin or claim its mine.. I just want to view a couple of images and categories to my clients.
Is this OK? Will they sue me?
If you use a copyrighted work in a way that is normally an exclusive right of the copyright holder (redistributing the work, creating a derivative work, etc.), and your use has not been licensed by the copyright holder, then you are committing copyright infringement. The decision of whether or not to sue you for copyright infringement is entirely up to the individual copyright holder.
That said, if you've downloaded the open-source version of the code, you have already been granted a license to use the work under the terms of the GPLv3. If you don't want to pay for a commercial license, then you must follow the terms of the GPLv3. If your use correctly obeys the GPLv3, then your use is licensed and you cannot be successfully sued for such use. (Note that they could still file suit against you -- anyone may do so at any time, for more or less any reason -- but their suit will almost certainly not prevail, because it would be completely baseless.)
If you use violates the GPL, then you would be operating outside the scope of the license grant and you would be liable for infringement. For example, if you do not also make your work available under the GPL (or a GPL-compatible license) when you distribute it, and appropriately make your human-readable source code available, then distribution of your code combined with Isotope would violate the GPL.
If you are selling the code you write to your clients, and they do not wish to abide by the terms of the GPL, I would suggest you (or your client(s)) purchase a license to relieve them of the requirement to make their source code available.
Because the previous question does not make it clear, IMO:
Isotope is Javascript. You distribute it as part of the Javascript on your website. That means your website is a Derived Work, and must itself be licensed under the GPLv3 (or under the commercial license terms, which in this case is an alternative).
However, you can still charge your clients for configuring & testing that it works as they want it. GPL doesn't prevent you from making money, you just have to abide by the GPL rules when doing so.
