Yes it was the first popular tracker that was developer centric, specifically agile (arguably Scrum), with story points being a very key (pivotal? pun) feature.

Yes it was the first popular tracker that was developer centric, specifically agile (arguably Scrum), with story points being a very key (pivotal? pun) feature. It was also extremely opinionated (i.e. bugs don't get points). This made it very predictable and easy to get started on. I liken PivotalTracker to a Ferrari. It does one thing and it does it well while JIRA is like your 18 wheeler. It'll also get you A-B, but you can bring everything "in case" you might need it and modify it to hell and back. It can even carry your Ferrari. But getting it setup and moving is a nightmare. Even simple searching your history is an exercise in complexity. Of course as with anything opinionated, if you wanted to do something outside of its core philosophy set, you basically couldn't. For better for worse, this really meant you were at least waist deep in agile's. When Agile+Scrum first started becoming popular it was very well received because fundamentally it gave a better framework for business to understand how developers worked other than promising deadlines. But, it's success was its own poison well... that's a different story.