1. The folder Secure Distributable contains a secured (obfuscated) version of Try & Buy whcih you can use when developing and distributing your applications. By default, the library is named System.Evaluation. Always use the secure distributable library to prevent malicious end-users from cracking the library and thus compromising your softwares. You can also find the same library in the folder bin/Debug/Secured located within Try & Buy's project folder.
2. The source code provides a demo for both C# and VB.NET so feel free to choose your language of choice. There is no Visual C++ demo currently, but may be considered in future.
3. There is a well documented PDF that fully explains all the aspects of the library - from its features, to licensing and so much more. You can always use this as a point of reference as you build your licensed products.