Rocket.Chat
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Comparison · Comms
Slack vs Roundcube
A side-by-side editorial comparison of Slack and Roundcube — release velocity, themes, recent moves, and the top alternatives to consider.
Slack vs Roundcube: at a glance
What is Slack?
Slack's app platform is being rebuilt around agents, with the SDKs clearing old ground behind it.
Slack's developer changelog currently runs on two tracks. One is agent infrastructure: agent apps now receive context about whatever channel, DM, thread, canvas, or list the user has open when they message the app, and a new manifest-declared messaging experience defines how agents converse. The other is SDK maintenance at a steady clip — Bolt for JS v5, a batch of Node Slack SDK majors, and three CLI releases inside a month.
What is Roundcube?
After four years, Roundcube 1.7 lands — and the release stream is otherwise all CVEs
Roundcube maintains two lines in lockstep: 1.6 as LTS and 1.7 as stable, with security fixes released to both on the same day. The vulnerability stream is heavy and varied — stored XSS via an unescaped attachment MIME type (CVE-2026-54432), a pre-auth SQL injection in the virtuser_query plugin, CSS injection through SVG animate, SSRF bypasses via local address URLs, an infinite loop in the TNEF decoder. Version 1.7.0, released in May after almost four years of development, is the only feature release in the window.
Slack vs Roundcube: editorial side-by-side
Slack
6.3COMMSCOLLAB
Slack's app platform is being rebuilt around agents, with the SDKs clearing old ground behind it.
◆ Current state
Slack's developer changelog currently runs on two tracks. One is agent infrastructure: agent apps now receive context about whatever channel, DM, thread, canvas, or list the user has open when they message the app, and a new manifest-declared messaging experience defines how agents converse. The other is SDK maintenance at a steady clip — Bolt for JS v5, a batch of Node Slack SDK majors, and three CLI releases inside a month.
◆ Where it's heading
The expansion is happening on the agent side while the SDK work removes rather than adds: axios swapped for native Fetch, Workflow Steps from Apps deleted, Node 20 set as the floor. Alongside that, a new Block Kit container block and the switch to pulling desktop notification text from blocks first both push more of the app experience into structured, app-rendered surfaces. Read together, Slack is moving the platform's center of gravity from configured workflow automation toward apps that hold a conversation with context.
◆ Prediction
Expect the next platform releases to widen what agents can receive and render — more context surfaces passed automatically and more Block Kit primitives to display results — while the CLI and SDKs keep their current maintenance cadence.
Roundcube
5.0COMMS
After four years, Roundcube 1.7 lands — and the release stream is otherwise all CVEs
◆ Current state
Roundcube maintains two lines in lockstep: 1.6 as LTS and 1.7 as stable, with security fixes released to both on the same day. The vulnerability stream is heavy and varied — stored XSS via an unescaped attachment MIME type (CVE-2026-54432), a pre-auth SQL injection in the virtuser_query plugin, CSS injection through SVG animate, SSRF bypasses via local address URLs, an infinite loop in the TNEF decoder. Version 1.7.0, released in May after almost four years of development, is the only feature release in the window.
◆ Where it's heading
The arc is a long-lived webmail codebase paying down structural risk. 1.7.0's headline changes are defensive rather than user-facing: a mandatory public_html/ entry point so installations aren't exposed by default, improved OAuth2/OIDC support including discovery and logout, removed code bloat and automated code style and quality checks. Everything since has been paired security releases across both lines, several of them reporting classes of bug — sanitizer bypasses, injection through plugin queries — that the 1.7 hardening work is aimed at. Expect the security cadence to stay high while the 1.6 LTS remains supported.
◆ Prediction
Expect continued same-day paired security releases on 1.6 and 1.7, with 1.7.x accruing incremental OIDC and sanitizer hardening before any 1.8 work becomes visible.
Alternatives to Slack and Roundcube
Other Comms products tracked by Sparkpulse, ranked by recent ship velocity. Each card links to a full editorial trajectory and lets you pivot into a head-to-head comparison with either Slack or Roundcube.
Chatwoot
Chatwoot added voice, then pointed its AI agent at the tickets it already resolved.
Mailu
A mail server whose entire visible output is patching other people's code.
Signal Desktop
Signal's beta train is quietly handing group admins real moderation powers.
Notion
Notion is turning itself into the place other companies' agents come to work.
Bird
Monthly digests showing AI chat latency cut hard, in a feed that repeats itself
See all Slack alternatives → · See all Roundcube alternatives →
Recent activity from Slack and Roundcube
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 1d agoSlackRelease: Slack CLI v4.6.0
- 10d agoSlackRelease: Slack CLI v4.5.0
- 16d agoSlackRelease: Bolt for JS v5
- 17d agoSlackRelease: Multiple Node Slack SDK package updates
- 18d agoSlackDesktop notifications now pull text from blocks first
- 26d agoRoundcubeRoundcube LTS patches attachment XSS, SSRF and a TNEF loop
- 26d agoRoundcubeRoundcube 1.7 gets the same attachment XSS and SSRF fixes
- 29d agoSlackAgent context has landed ⚡
- 1mo agoRoundcubeRoundcube LTS fixes a pre-auth SQL injection in virtuser_query
- 1mo agoRoundcubeRoundcube 1.7.1 carries the pre-auth SQL injection fixes
- 2mo agoRoundcubeRoundcube Webmail 1.7.0 ⚡
- 4mo agoRoundcubeRoundcube 1.6.15 fixes an SVG animate bypass and search regressions
Frequently asked questions
What is the difference between Slack and Roundcube?
They serve adjacent needs but don't currently overlap on shipped themes. Slack is currently shipping more aggressively (velocity 6.3 vs 5.0), with 1 editorial sparks in the last 30 days against 0. See the at-a-glance table above for a side-by-side breakdown of velocity, recent sparks, and editorial themes.
Is Slack better than Roundcube?
Sparkpulse doesn't pick a winner — we score release velocity, not feature parity. Slack is currently shipping more aggressively (velocity 6.3 vs 5.0), with 1 editorial sparks in the last 30 days against 0. For your specific use case, the alternatives sections above list other Comms products to evaluate alongside.
What are the best alternatives to Slack?
Top Slack alternatives in Comms are ranked by recent ship velocity. Browse the "Slack alternatives" section above for the current picks, or visit /alternatives/slack for the full list with editorial commentary on each.
What are the best alternatives to Roundcube?
Top Roundcube alternatives in Comms are ranked by recent ship velocity. Browse the "Roundcube alternatives" section above for the current picks, or visit /alternatives/roundcube for the full list with editorial commentary on each.