Summary: Bought this as it was certified to work in Linux by manufacturer. I am not a Linux expert and was searching around for how to compile drivers for the device when I got the idea to just plug it in and see what happens and, Voila!
Summary: I was also able to get this working on my Macbook Pro (Early 2011) running 10.10.2 Yosemite. The older models (A1) of this adapter used a Ralink chipset, but the newer ones (B1), which was the one I received, use the Realtek chipsets, namely RTL8192CU.
Summary: Hooks to the wireless fine. It's a 1000% improvement from my laptop which has some issue and it takes FOREVER to connect. This does it immediately. I do have an issue with the interface; it's clunky and not descriptive in what it wants or does.
Plug and Play on Win8.1, I needed to tinker with Linux
3 September 2014
Summary: I have not had any issues on Windows 8.1, it was plug and play. I had some problems getting it to work on Linux, so I was hoping by posting my experience with it I could save some people time.