Slack

Slack brand colours

Extracted from the artwork and ranked by how much of the mark each covers — not from a brand book, so treat them as observed rather than official.

Slack is the messaging layer most engineering organisations run on, and for developers it is as much a platform as a chat client: incoming webhooks, the Events API, slash commands, interactive Block Kit messages, Workflow Builder, and — more recently — the place CI, on-call and coding agents report into. Owned by Salesforce since 2021. Free-tier message retention limits and per-seat pricing are the usual reasons teams evaluate alternatives, which are Microsoft Teams where Office is already paid for, Discord for community-facing work, Zulip for threaded technical discussion, and Mattermost or Rocket.Chat for self-hosting. Its relevance to toolweight is as an integration target: notification delivery into Slack is a checkbox on most monitoring, deployment and status products, and the quality of that integration varies far more than the checkbox suggests.