[repsilat]

Maybe it was 6gu.nz (site broken) https://www.youtube.com/watch?v=afXzeCuUuhU. I wrote it about 5 years ago and probably mentioned it in a couple of comments here. It had draggable tables on the normal 2d grid, with references between them.

[AstroJetson]

Wow, that is very, very cool. The wayback machine has it, with a test page that works and the docs. Demo is here:

https://web.archive.org/web/20200114060557/https://my.6gu.nz