https://www.atlassian.com/licensing/purchase-licensing Atlassian probably fits t...

		pquerna on July 18, 2015 \| parent \| context \| favorite \| on: The Unicorn Club 2015: Learning from Billion-Dolla... https://www.atlassian.com/licensing/purchase-licensing Atlassian probably fits the bill more and has proven revenue on it, while Slack is more... "SaaS" in my mind, and really hasn't proven long term revenue traction yet, though it is certainly looking good for them.