Executables for the EBM on MacOS and Windows: The executables are no longer supported. I'm sorry I can't help you if they don't work on your computer. I no longer have a working compiler for them. The algorithm is explained in detail in the book and is straightforward to code.
The Spreadsheet EBM: This spreadsheet version of the EBM contains a relatively easy explanation of how a numerical model works.
The Spreadsheet for the 'Stocker' calculations.
The QR codes are made to work by redirects attached to the links. Over time, these links have gone away or are otherwise broken. In some cases, browsers opt not to redirect to the resource. If you're having difficulty, there should be enough information in the book related to the QR code for you to find it with Google. This PDF file contains details of the links used at time of going to press in 2014.If you have questions, contact the authors via kendalmcguffie[at]gmail.com.