Rspamd
Rspamd 4.3 fixes SPF evaluation order and rejects weak DKIM keys, with results that change.
Comparison · Comms
Pixelfed vs Slack
A side-by-side editorial comparison of Pixelfed and Slack — release velocity, themes, recent moves, and the top alternatives to consider.
Pixelfed vs Slack: at a glance
What is Pixelfed?
Pixelfed 0.15.2 ships the PHP RCE patches and turns cached timelines on for everyone.
Pixelfed v0.15.2 is an urgent security update: Docker images pick up the patched PHP for this month's two remote code execution CVEs and are rebuilt with updated CAs after the eMudhra compromise. It also makes cached timelines the default, removing two experimental flags, and bundles timeline and WebFinger fixes.
What is Slack?
Slack now hosts any A2A agent without Slack-specific code.
Slack's developer channel is almost all agent plumbing. On 10 November Slack became an A2A (Agent2Agent) client: a team hosts its own agent, publishes an Agent Card, and Slack calls it when people talk to it, with no request URL, event handling or Slack-specific logic. This follows Slackbot skills managed through Web API methods, a Slack CLI that points coding agents to the Slack MCP server, and a new requirement that Work Objects embeds allow the slack-mcps.com frame ancestor.
Pixelfed vs Slack: editorial side-by-side
Pixelfed
5.0COMMS
Pixelfed 0.15.2 ships the PHP RCE patches and turns cached timelines on for everyone.
◆ Current state
Pixelfed v0.15.2 is an urgent security update: Docker images pick up the patched PHP for this month's two remote code execution CVEs and are rebuilt with updated CAs after the eMudhra compromise. It also makes cached timelines the default, removing two experimental flags, and bundles timeline and WebFinger fixes.
◆ Where it's heading
Pixelfed has moved quickly through 0.14.5 and 0.15 with federation fixes and new APIs, and now an upstream security patch. The notes say heavy refactoring will continue toward a Nuxt-based web UI, so the near term is more churn in the front end.
◆ Prediction
Expect more 0.15.x patches for regressions from the refactor, with the Nuxt web UI as the next visible milestone.
Slack
6.3COMMSCOLLAB
Slack now hosts any A2A agent without Slack-specific code.
◆ Current state
Slack's developer channel is almost all agent plumbing. On 10 November Slack became an A2A (Agent2Agent) client: a team hosts its own agent, publishes an Agent Card, and Slack calls it when people talk to it, with no request URL, event handling or Slack-specific logic. This follows Slackbot skills managed through Web API methods, a Slack CLI that points coding agents to the Slack MCP server, and a new requirement that Work Objects embeds allow the slack-mcps.com frame ancestor.
◆ Where it's heading
Slack is lowering the cost of putting outside agents in front of its users: first skills as code, then MCP pointers for coding agents, now a standard protocol in place of the Slack app model for agents. The platform is positioning itself as the place where agents built anywhere meet the people who use them.
◆ Prediction
Expect more A2A follow-ups, such as agents appearing in Slackbot or skills surfaces and richer Agent Card features, given how fast the agent releases have stacked up since October.
Alternatives to Pixelfed and Slack
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 Pixelfed or Slack.
Twilio
Twilio's voice AI stops cutting callers off mid-sentence, using its own turn-taking model.
Salesmsg
Salesmsg adds call-back requests and a one-click Emergency Stop for all outbound texts.
Element
Element 1.12.35 follows the call picture-in-picture release with one desktop storage fix.
Krisp
Krisp moves call transcripts and live captions to cloud transcription in KrispCX 2.84.4.
Misskey
Misskey 2026.11 ships: a leaner start script, and Node.js 22 no longer boots.
See all Pixelfed alternatives → · See all Slack alternatives →
Recent activity from Pixelfed and Slack
Latest ship moves from both products, interleaved chronologically. ⚡ = editorial spark.
- 4d agoSlackBring your A2A agents to Slack ⚡
- 8d agoSlackWork Objects embeds require the slack-mcps.com frame ancestor
- 10d agoSlackSlack CLI 4.13 tells coding agents about Slack MCP and Skills
- 10d agoSlackSlack Skills Plugin installs in Claude Code from its own marketplace
- 12d agoSlackUpdated low-usage submission criteria for Slack Marketplace apps
- 15d agoSlackSlack CLI 4.12.0, the fourth CLI release in October
- 23d agoPixelfedv0.15.2 - Security Update: PHP RCE + CA Update Compromise
- 27d agoPixelfedv0.15.1 - Fix Languages regression
- 1mo agoPixelfedPixelfed 0.15 RC adds account-delete API, drops PHP 8.3
- 1mo agoPixelfedPixelfed 0.14.5 RC fixes boost federation, adds FEP-6757
- 1mo agoPixelfedv0.12.12
Frequently asked questions
What is the difference between Pixelfed and Slack?
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 Pixelfed better than Slack?
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 Pixelfed?
Top Pixelfed alternatives in Comms are ranked by recent ship velocity. Browse the "Pixelfed alternatives" section above for the current picks, or visit /alternatives/pixelfed for the full list with editorial commentary on each.
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.