I’ve been engaged (with a great team) in building argument mapping software for over a decade now.  Its been an uphill battle most of the way.  The acid test of success is sales, but there are other measures, such as positive, insightful feedback from users who “get it,” i.e. understand what we’ve done.  Such as the feedback which arrived today:

“I could go on at length about how much I like Rationale.  Where to start.  Where it end.  First of all a big sincere thanks to the designers – developers.  Your product is superlative.  It functions flawlessly, doesn’t crash, no small accomplishment.  The conceptual method of Rationale diagramming is really great.  It is easy and fun to use.  If more readers were aware of the methodology gently introduced in Rationale’s tutorials, they would reach more intelligent conclusions and be more demanding of writers.  I am just starting the final exercise sets in Rationale.  They appear to have a pretty good dose of philosophy, a fair stretch made easy by your excellent tutorials. Rationale is a truly different, truly useful product.”