[jrockway]

I did a little bit of this supporting when I worked at a bank. Apparently there is multicast networking that you can plug into spreadsheets, so the "output" of a spreadsheet can be used as inputs on other people's workstations and it updates in real time. (I would say this was before Google Docs was a thing, but I don't think it actually was. But Google Docs wasn't widely used anywhere at the time.)

This all blew up one day causing the bank to lose money. My team was supposed to fix it or whatever, because we were the "market data" team. I ended up writing a small program to send a multicast message and record how long it took to come back, and graphed it over time with ... rrdtool! Once the network/transport layer was ruled out as the problem, some trader came back and said it was a bug in their spreadsheet. (This was of course months of early morning conference calls. But having data about the network was a new thing.)

(Oh yeah, someone complained that the author of rrdtool's name appeared on all the charts, so I patched it to not do that. Sorry. Sometimes open source is more about the taking than the giving :( I was young and naive.)