How much do people use dependencies in jira etc? Seems that one ought to be able to create a plugin that would automatically generate and update this graph for any issue with dependencies.
However, Bugzilla only has one flavour of dependency ("blocks"), whereas JIRA implements the whole Allen Interval Algebra (which, however, only those people use who have ever wondered why the number of Allen relations is exactly 13).
There are plugins, but I can't add plugins at will at work. People don't use deps properly though - GIGO.