Hi Pedro,
Yes, you can use TurboActivate (the part of LimeLM you include with your app) on Mac, Linux, and Windows. Also, since unity uses C# to work with external libraries you can use our pre-written C# bindings (the TurboActivate.cs file in the API download). It's in the "API\CSharp" folder.
Here's an article on using TurboActivate with C#.