Initially known as Tiny Speck, the company we now know as Slack first worked on a Flash-based online game called Glitch, which developers around the country worked on for close to four years. [10] [12] Yet at some point, the team became less interested in Glitch and more interested in IRC, “the ‘80s era communication tool they were using to collaborate over long distances and long periods of time.” [12] The team appreciated that IRC allowed them to focus in on projects while tuning out other email inbox noise, and it wasn’t long before the entire company pivoted toward communications.

https://growthhackers.com/companies/slack-fastest-growing-b2b-saas-business-ever/