[mwilliamson]

Author here! The open sourced code was rewritten from scratch, not least because the original version was in C# while the open source version is in JavaScript. So, the same idea, but an entirely new implementation.

I forget exactly what conversations I had, but it was also very clear that they had no problem with me doing so since it doesn't really have any connection with their core business. If I wanted to, I suspect I could have open sourced the original version so long as I stripped out the stuff that was specific to the company.