Comment by kfogel

Source being on GitHub does not equal "is open source". Restrictions on commercial use are incompatible with open source. The Open Source Initiative, which coined the term and evaluates licenses for compatibility with the Open Source Definition (see https://opensource.org/definition), is crystal clear on this point: if your license has a field-of-use restriction -- such as a restriction on commercial use -- then it's not open source. This is why Numworks is careful not to describe their software as "open source", to their credit.