Slack is a cloud-based team communication and collaboration platform developed by Slack Technologies. Founded in 2009 in Vancouver, British Columbia, it began as an internal tool for Stewart Butterfield's company, Tiny Speck, during the development of an online game called Glitch. Realizing the potential of their internal communication tool, the company pivoted to focus on developing it into a standalone platform. In August 2014, the company officially changed its name to Slack Technologies. Slack's name is an acronym for "Searchable Log of All Conversation and Knowledge".
Slack provides various IRC-style features, including organized channels for specific topics, private groups, and direct messaging. It integrates with over 2,500 apps and offers an API for users to develop applications and automate processes. In 2021, Slack was acquired by Salesforce for $27.7 billion. While Stewart Butterfield was CEO, Lidiane Jones succeeded him as CEO after he left in December 2022. As of January 2026, Slack has an estimated 47.2 million daily active users and 79 million monthly active users. Slack has been rolling out a new AI agent across January and February 2026, enhancing the existing Slackbot with AI-powered features.
