python

xllify is a packaging tool and runtime that allows functions written in Luau and Python to be used as high-performance custom functions in your Microsoft Excel workbooks. In a bizarre collision of 1990s style development (the Excel C SDK) and 2025 era AI, I’ve been experimenting with having a Claude agent write Excel custom functions for xllify! As Excel itself is now fat and 40 years old, it could be donning ill-fitting running gear and developing an irrational interest in coffee beans....

Back in August, I introduced xllify. This was a project I started when in-between contracts. I’ve since distilled my definition of xllify to: xllify is a packaging tool and runtime that allows functions written in Luau and Python to be used as high-performance custom functions in your Microsoft Excel workbooks. Go have a look! Things have evolved. As with all projects, I try to ruthlessly simplify and make things faster....

This project started when my son asked me for a replica train departures board for Christmas. I thought this was a great idea and this looks to be a really neat implementation, but I wanted us to have a go at building one ourselves. I promised that if we failed miserably I’d buy him one! After getting some off-the-shelf code up and running, I wanted to rethink the software. The resulting code is available on GitHub....