Slack

Slack launched in 2013 as a side project at a failed gaming studio and became the fastest-growing business app of its era. Salesforce bought it in 2021 for $27.7 billion. Today it's the default messaging layer for millions of teams who organize work into channels instead of drowning in email threads.

What Makes Slack Special

Channels are the whole idea. Instead of CC-ing eight people on an email, you post in #marketing and the conversation stays put, searchable, with context anyone can scroll back through. Threads keep side discussions from cluttering the main feed. The search is genuinely good — I can find a decision made 14 months ago in about four seconds.

The integration catalog is the real moat. Over 2,600 apps in the directory, plus a solid API and Workflow Builder for no-code automations. GitHub, Jira, Google Drive, Zoom, Salesforce — they all pipe notifications and actions straight into channels.

Day-to-Day Experience

It's fast and the desktop app feels native even though it's Electron. Huddles give you lightweight audio (and now video) calls without scheduling anything — you click a button and talk. Clips let you record short async video messages. Notifications are configurable down to the keyword, which matters once you're in 40 channels.

The Honest Trade-offs

The free plan changed in 2022: you now get 90 days of message history instead of 10,000 messages forever. For a small team that's a real downgrade. Pricing is per-user per-month, so a 100-person company on Business+ pays around $15,000/year. Slack can also become a focus-killer — the always-on culture is a feature and a bug. And Microsoft Teams comes bundled free with Microsoft 365, which is hard to argue against on cost alone.

Who Should Choose Slack

Startups, tech teams, agencies, and any company that already runs on a stack of SaaS tools. If your work happens across many apps and you want one searchable hub tying them together, Slack is still the best at that job. Teams already paying for Microsoft 365 should weigh Teams first.