Slack is a cloud-based freemium cross-platform instant messaging service created by Slack Technologies and currently owned by Salesforce. While initially developed for professional and organizational communications, it has also been adopted as a community platform. Users can communicate through text messaging, file and media sharing, voice and video calls in private chats or within communities called "workspaces." The application incorporates IRC-style elements such as persistent chat rooms (referred to as channels) organized by topic, private groups, and direct messaging. In addition to these online communication features, Slack can integrate with other software. Slack can be accessed through web browsers, and dedicated clients are available for Windows, Linux, MacOS, Android, and iOS. In the past, a client was also available for Windows Phone devices, but support for it was discontinued in June 2018.
History
Slack originated as an internal communication tool used within Stewart Butterfield's company, Tiny Speck, during their work on the development of Glitch, an online game. These communication tools were initially built around the Internet Relay Chat (IRC) protocol and included scripts designed to automate and organize file exchanges among their development team. However, in October 2012, Stewart Butterfield came to the realization that Glitch was not going to bring necessary profits. As a result, he decided to change the direction of his company and repurpose the communication tools they had developed into a new product.
In 2012, Stewart Butterfield decided to name their upcoming product "Slack," which he said was derived from the phrase "Searchable Log of All Conversation and Knowledge," replacing the previous codename "linefeed."
In August 2013, Slack was launched to the public and continued to maintain compatibility with IRC, reflecting its origin. Additionally, it was also compatible with XMPP messaging protocols. However, in May 2018, the company chose to close down these corresponding gateways due to limitations inherent in those protocols.
On July 26, 2018, Slack acquired HipChat and Stride from Atlassian, with plans to shut down both services in February 2019 and migrate their users to Slack.
In June 2019, Slack went public through a direct public offering to reach a market value of US$19.5 billion.
In July 2020, Slack acquired Rimeto, a startup specializing in employee directories and profiles, with plans to rename the service and operate it as a standalone app. Almost a year later, in June 2021, its functionality launched as an optional feature within Slack named "Slack Atlas."
On December 1, 2020, Slack and Salesforce announced an agreement for Salesforce to acquire the company for approximately $27.7 billion, marking one of the most significant tech acquisitions at that time. The acquisition was successfully completed on July 21, 2021.
On December 5, 2022, Salesforce announced that Stewart Butterfield was leaving Slack, and he would be succeeded by Lidiane Jones, an executive vice president at Salesforce.
Incidents
In March 2015, Slack announced it had been hacked for over four days in February 2015 and that some data associated with user accounts had been compromised, including email addresses, usernames, hashed passwords, phone numbers, and Skype IDs. In response to the attacks, Slack added two-factor authentication to its service.
On January 4, 2021, Slack suffered a significant outage that lasted several hours. From 10 AM ET until 3 PM ET, users could not log in, send or receive messages, place or answer calls, or use Slack connections. After 3 PM, most of the core features became operational, except for push notifications, email, and third-party integrations including Google Calendar and Outlook Calendar.
In 2022, Slack suffered widely reported outages on February 22, March 9, July 26.
On 31 December 2022, Slack announced that its private GitHub repositories had been compromised during the previous weeks, using stolen security tokens.
Features
Slack offers many IRC-style features, including persistent chat rooms known as channels, which are organized by topic, as well as private groups and direct messaging functionalities. All content, including files, conversations, and people, is searchable within Slack. Users can express their reactions in the form of emojis to any message. Message history on Slack is limited to 10,000 most recent messages on the free plan.