Slack

What is Slack?

Slack is a team messaging platform that serves as the central communication hub for organizations, made by Slack Technologies (acquired by Salesforce in 2021). It organizes workplace conversations into channels by team, project, or topic, enabling asynchronous and real-time communication alongside direct messaging, audio huddles, and video calls. The platform supports file sharing, message threading, and search across conversation history, making it the default choice for distributed and co-located teams across industries.

The platform's extensibility defines its ecosystem. Slack's Workflow Builder enables users to automate repetitive tasks without coding—triggering actions across connected applications, scheduling messages, or collecting information through forms. The Slack Marketplace hosts thousands of pre-built apps and integrations, connecting to tools like Salesforce, GitHub, Jira, Google Drive, Zapier, and hundreds of others. The Agentic Platform allows organizations to build custom AI agents and bots that operate within workflows, performing tasks like data lookups, code review, or deal updates. Slackbot, Slack's built-in AI assistant, integrates Claude (via Anthropic partnership), offering conversation summarization, web search, data visualization from connected sources, and contextual answers based on workspace history. Slack Atlas provides organization charts and user profiles, while Enterprise Search indexes all workspace data for discovery.

The platform uses a freemium pricing model: a limited free tier supports small teams with message history and core features, while Pro, Business+, and Enterprise+ tiers unlock unlimited message history, advanced security controls, compliance tools, and priority support. Enterprise customers gain single sign-on, data residency options, and custom contract terms. Usage spans engineering, sales, customer service, project management, and HR departments.

Slack faces competition from Microsoft Teams (bundled w