My colleagues wrote PyF, using the same idea of code written in boxes that you link together. It saved all code blocks in an XML file. We used it on financial

My colleagues wrote PyF, using the same idea of code written in boxes that you link together. It saved all code blocks in an XML file. We used it on financial data. One of our programs was so complex that we fell back on using a text editor to directly edit the XML instead of using the GUI. The project was published on pypi but for some reason the source code was never published and it is in the same state since 2011, using python 2 and all. I left the place 2 years ago but my colleagues who still work there said it's still mission-critical. A kind of Cobol.