Slack (software)

Slack (software)
Name	Slack
Developer	Salesforce
Released	August 2013
Operating system	Cross-platform
Genre	Collaborative software
License	Proprietary software

Slack (software). Slack is a proprietary business communication platform developed by the American software company Salesforce. Launched in 2013, it is designed to facilitate team collaboration through organized persistent chat rooms, direct messaging, and extensive third-party integrations. The platform has become a central tool in modern corporate communication, competing with services like Microsoft Teams and Discord.

History

The development of Slack originated from the internal communication tools created by Stewart Butterfield, Cal Henderson, and their team while working on the now-defunct video game project Glitch at the company Tiny Speck. Recognizing the value of their custom IRC-inspired tool, the team, led by Butterfield, pivoted to develop it as a standalone product. Slack was officially launched to the public in August 2013, quickly gaining traction within the Bay Area tech community and beyond. Significant milestones include a major funding round led by Kleiner Perkins in 2014, surpassing one million daily active users in 2015, and its direct listing on the New York Stock Exchange in 2019. In December 2020, Salesforce announced its acquisition of Slack Technologies, Inc. for over $27 billion, a deal finalized in July 2021.

Features

Slack organizes communication into dedicated spaces called channels, which can be public or private, for topics, projects, or teams. Core features include persistent chat, file sharing, and search across all conversations and uploaded documents. A defining characteristic is its robust support for API-driven integrations, allowing connections to thousands of external services like Google Drive, GitHub, Jira, and Zoom. Other notable features include voice calls and video conferencing, screen sharing, workflow automation through Slackbot, and customizable notifications. The platform supports emoji reactions and threaded replies to keep conversations organized.

Architecture and infrastructure

Slack is built as a cloud-based, multi-tenant SaaS application, primarily hosted on Amazon Web Services. Its backend is constructed using a microservices architecture, with core services written in PHP and Java, while the real-time messaging layer utilizes the WebSocket protocol and the Erlang runtime system for handling concurrent connections. The client-side applications for Windows, macOS, Linux, iOS, and Android are built using the Electron framework and React Native, respectively. For data storage, Slack employs a combination of MySQL databases and the Apache Cassandra distributed database system.

Business model and pricing

Slack operates on a freemium business model, offering a free tier with limited message history and integrations alongside several paid subscription plans. The primary paid plans are the Pro, Business+, and Enterprise Grid tiers, which offer unlimited message history, enhanced security controls, guaranteed uptime SLAs, and dedicated support. Pricing is typically per user per month, with discounts for annual commitments and for larger organizations on the Enterprise Grid plan. Revenue is also generated through partnerships and its Slack App Directory, which features both free and paid third-party applications.

Reception and impact

Upon release, Slack received widespread critical acclaim, winning awards like the Crunchies "Best New Startup of 2014" and rapid adoption by companies such as IBM, Target, and *Time* magazine. Reviewers from The New York Times and The Wall Street Journal praised its intuitive design and powerful search functionality. Slack is widely credited with reducing internal email volume and transforming workplace culture in many organizations, though it has also faced criticism for potential information overload and productivity disruption. Its success spurred significant competition, most notably from Microsoft's Microsoft Teams, which is bundled with Microsoft 365.

Security and compliance

Slack implements multiple layers of security, including data encryption both in transit and at rest, and supports single sign-on via protocols like SAML and OAuth. The platform offers administrative tools for managing members, devices, and data retention policies. Slack maintains compliance with various industry and regional standards, including ISO/IEC 27001, SOC 2, the HIPAA for healthcare data, and the GDPR for the European Union. Enterprise Grid customers have access to advanced security features like enterprise key management and data loss prevention integrations.

Category:Collaborative software Category:Proprietary software Category:Cloud computing