Our story is very similar. I wrote a small library for converting XLSX and XLS f...

Our story is very similar. I wrote a small library for converting XLSX and XLS files to CSV. Over the years, that grew into one of the most popular open source libraries on npm/github: https://github.com/SheetJS/sheetjs

Back in 2015, 'patio11 reached out to us. In addition to a structured license purchase, he gave great insights and actually wrote a blog post about the experience https://www.kalzumeus.com/2015/01/28/design-and-implementati...

Today, we offer paid software builds to solve related problems and it allows us to work on SheetJS full-time!