JIRA offered a good compromise between closed and open source: full source code was available, which enabled local custom modifications to prove out the viability of enhancement requests. Atlassian also provides free JIRA to open-source projects, e.g. keep code on Github, move issue tracking to cloud-hosted JIRA for workflow not supported by Github issues.
It is encouraging to see a bootstrapped company reach IPO, even if it took them a decade to reach their $3B valuation compared to Github's attainment of a $2B valuation in a much shorter time. Atlassian's forward-thinking private investors provided liquidity to employees, which supported their long road to the public market. From a 2014 interview, http://fortune.com/2014/04/10/atlassian-the-3-3-billion-soft...
"The $150 million it recently raised isn’t going into its bank account — instead, its new investors are buying shares from past and present employees in an effort to offer workers some liquidity and retain talent ... 'the Accel Partners round was mostly about founders, and this [T. Rowe Price] one is about employees. Now neither of the founders are selling anything. So this is a little different. We’ve been profitable for 10 years, so we don’t need the cash, we have a lot of cash in the bank. It’s more a case of wanting to get a partner [that knows about public markets] on board..'"
From a 2011 review of Atlassian culture and self-service sales, http://www.managementexchange.com/story/its-culture-stupid-h..., with a talk about internal systems: https://youtube.com/watch?v=mALn4nyi7Qs
"Atlassian CEOs have instilled an information culture throughout the company with the core value of "Open Company, No Bullshit". The result is a bottom-up democracy of information where information sharing is the norm and information hoarding is a foreign concept ... Product pricing is public, including discount policies. Prospective customers can download software and try it free for 30 days. All documentation is public and available for anyone to access. Bug reports and feature requests are public, allowing people to 'vote' on their preferred features."