This is probably not the repository that you are looking for. This repo comprises a discontinued experiment to change the design of QuantLibXL. If you want to compile QuantLibXL from source code, then the repo that you need is: https://github.com/eehlers/QuantLibAddin-Old And the documentation is: https://www.quantlib.org/quantlibaddin/build_qlxl.html That doc explains how to retrieve the source code from packaged tarballs. You can instead retrieve the source code from the QuantLibAddin-Old repo and the build is otherwise the same.