DarkGDK 2.0 is now available for free. The last official release was the the commercial RC4 and is compatible with older versions of PureBasic but will work fine with any version of C++.
I spent a lot of time developing this product but it was never very successful. It extend a product whose support had more or less ended and targeted a very niche market. It's still very usable and I've received a few messages over the years from former users asking about the product. As I haven't actually made a sale in years, I feel that this product should be retired and I'm not making it available for free for both personal and commercial use.
I've attached the last public release to this thread for download, as the official website is no longer online.
To use the license file, choose the option in the installer to skip online authorization. You can copy this file into the license folder after it's installed.