Slack

Slack is a cloud-based team communication and collaboration platform originally developed by Stewart Butterfield, Eric Costello, Cal Henderson, and Serguei Mourachov. Slack's origin story is one of the most famous pivots in technology history: it was created as an internal communication tool during the development of Glitch, an online game by Tiny Speck, the company founded by Butterfield in 2009. When the game failed, the team realized their internal messaging tool had far greater potential. Slack launched publicly in February 2014 and became one of the fastest-growing business applications in history, reaching one million daily active users within a year. The platform's name stands for 'Searchable Log of All Conversation and Knowledge,' reflecting its emphasis on making workplace communication organized and searchable. Slack introduced the concept of channels for organized topic-based communication, direct messaging, file sharing, and extensive third-party integrations through its app directory, which hosts thousands of integrations with tools like Google Workspace, Jira, Salesforce, and GitHub. Slack's 'Huddles' feature added lightweight audio and video calling, while Slack Connect enabled secure communication between different organizations. Salesforce acquired Slack in July 2021 for $27.7 billion, integrating it as the collaboration layer across the Salesforce platform. Under Salesforce's ownership, Slack has integrated AI features including conversation summaries and smart search, and continues to serve as the communication hub for millions of professionals worldwide.