I bet the data structures for this app look pretty much identical to this interface. It looks like the author read Joel Spolsky's "Painless Project Schedules",

I bet the data structures for this app look pretty much identical to this interface. It looks like the author read Joel Spolsky's "Painless Project Schedules", wrote a GUI to do that, then exposed all of the plumbing to allow endless tinkering. Sure, the interface is pretty sadistic for Yet Another Scheduling Tool, but maybe the original goal wasn't to make another FogBugz -- maybe it started as a prototype to explore different ways of munging data from project schedules. Comparing the original Joel article to the current Evidence-Based Scheduling approach of FogBugz, it's possible that even the HCI wizards at Fog Creek hacked together a few obtuse prototypes before finally settling on the right combination of plumbing and porcelain.