IIRC, there were several competitors with no clear leader [1] but Bugzilla was pretty popular. Then Trac [2] showed up with a clean UI which allowed it to gain

IIRC, there were several competitors with no clear leader [1] but Bugzilla was pretty popular. Then Trac [2] showed up with a clean UI which allowed it to gain mindshare among OSS projects. JIRA ultimately became the market leader due to having a product that sucked less than what was out there and being infinitely customizable. One of the things Atlassian did to gain mindshare was to gift large OSS projects, often under the ASF (Apache Software Foundation) banner, free licenses to JIRA and Confluence. FogBugz was popular if you were a regular reader of Joel’s blog or if you had heard of the Business of Software community. Outside of that bubble, it wasn’t that well known. 1: https://en.wikipedia.org/wiki/Comparison_of_issue-tracking_systems https://en.wikipedia.org/wiki/Comparison_of_issue-tracking_s... 2: https://en.wikipedia.org/wiki/Trac https://en.wikipedia.org/wiki/Trac