--- title: Docker builds its own VM engine, X open-sources its... description: Docker Desktop 4.86 ships Docker VMM, a self-built virtualization layer replacing the patchwork of libkrun, Hyper-V, and KVM across platforms. X released the... canonical: https://daily.dev/posts/docker-builds-its-own-vm-engine-x-open-sources-its-ranking-algorithm-keuat9ig5 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Docker builds its own VM engine, X open-sources its ranking algorithm | daily.dev og:description: Docker Desktop 4.86 ships Docker VMM, a self-built virtualization layer replacing the patchwork of libkrun, Hyper-V, and KVM across platforms. X released the... og:url: https://daily.dev/posts/docker-builds-its-own-vm-engine-x-open-sources-its-ranking-algorithm-keuat9ig5 og:image: https://api.daily.dev/og/posts/KeUAT9Ig5.png og:image:alt: Docker builds its own VM engine, X open-sources its ranking algorithm og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Docker builds its own VM engine, X open-sources its ranking algorithm **[Backend Digest](https://daily.dev/sources/backend_digest)** · 5 min read · 1 upvotes · 0 comments ## Summary Docker Desktop 4.86 ships Docker VMM, a self-built virtualization layer replacing the patchwork of libkrun, Hyper-V, and KVM across platforms. X released the full 'For You' ranking algorithm under Apache 2.0, showing exactly how weighted engagement predictions and safety enforcement interact. SOCAR published a detailed writeup on a self-healing AI agent system that cut a 4-hour incident recovery time down to automated fixes across 7,267 tickets. Ryan Dahl released celld, an open-source, self-hosted reimplementation of Cloudflare Durable Objects, and Rails 8.2 finally gets a fix for a nasty Puma-wedging race condition in ActionController::Live. ## Content **TLDR:** Docker Desktop 4.86 ships Docker VMM, a self-built virtualization layer replacing the patchwork of libkrun, Hyper-V, and KVM across platforms. X released the full 'For You' ranking algorithm under Apache 2.0, showing exactly how weighted engagement predictions and safety enforcement interact. SOCAR published a detailed writeup on a self-healing AI agent system that cut a 4-hour incident recovery time down to automated fixes across 7,267 tickets. Ryan Dahl released celld, an open-source, self-hosted reimplementation of Cloudflare Durable Objects, and Rails 8.2 finally gets a fix for a nasty Puma-wedging race condition in ActionController::Live. --- ## Docker builds its own virtualization engine, betting on unified runtime across platforms Docker Desktop 4.86 introduces Docker VMM, replacing the OS-specific backends (libkrun on macOS, Hyper-V/WSL2 on Windows, KVM/QEMU on Linux) with a single engine Docker controls end to end. The pitch is faster container startup, quicker host-container file I/O, and smarter idle memory reclamation, with Windows getting the biggest claimed win: Hyper-V-level isolation at speeds closer to WSL2, a tradeoff that's plagued that platform for years. Mac auto-upgrades now, Windows is opt-in, and Linux support (plus VMM becoming the default everywhere) is targeted for end of October 2026 — so treat this as promising but unproven at scale for a while yet. [Read more](https://daily.dev/posts/FXCcMZx5L) ## X open-sources its 'For You' ranking algorithm under Apache 2.0 The code shows the feed score is a weighted combination of predicted probabilities across favorites, replies, reposts, dwell time, follows, mutes, blocks, and reports — not a simple popularity contest. Following relationships boost ranking, newer accounts get a visibility bump, and repeated posts from the same author get suppressed, while safety/spam enforcement runs as an entirely separate layer that can remove a well-ranked post after the fact. It's a rare look at production-scale recommendation weighting, though enforcement rules, Grok prompts, and live production config are notably absent from the release. [Read more](https://daily.dev/posts/wwx5IxYpV) ## SOCAR's self-healing agent system recovers 7,267 tickets in two months SOCAR's parking-discount batch job was failing manual recovery at a 4-hour average, racking up roughly 300,000 failures and 165,000 refunds a year. Their fix was a LangGraph multi-agent system that mirrors how a human debugs — separate nodes for login, search, discount, check, compare — powered by Gemini 3.1 Pro at a few hundred won per recovery, with Playwright MCP feeding structured accessibility-tree snapshots instead of screenshots. The guardrails are the interesting part: credentials hidden from the LLM via closures, agent self-reports independently verified, Zod schemas replacing free text, and code changes limited to draft PRs a human still has to approve. It also caught a silent API version deprecation before it caused an outage. [Read more](https://daily.dev/posts/rIYeTfOF8) ## Rails Live streaming race condition that wedged Puma workers gets fixed for 8.2 Babylist traced a mysterious production hang — every Puma worker in a fleet going silent 17-20 hours after each deploy — to a race condition in ActionController::Live::Buffer. When a client disconnects mid-SSE-stream, Rails clears the internal queue without pushing the sentinel value that wakes the reader thread, permanently stranding the worker. After two weeks misdiagnosing it as a resource leak, they reproduced the hang on demand in staging, filed rails/rails#58047 and #58048, and got the fix merged by Aaron Patterson, targeted for Rails 8.2. Worth a bookmark if you run any Rails app with SSE at scale. [Read more](https://daily.dev/posts/EU2YHxDSR) --- ## Also notable - **Ryan Dahl releases celld, an open-source Durable Objects clone:** Celld reimplements Cloudflare's Durable Objects and Workers APIs on S3-compatible storage and Tokio instead of Cloudflare's infrastructure, with Dahl claiming $49/month versus Cloudflare's $415/month for 100 resident objects (a number Cloudflare disputes, citing $20.65 for idle objects). [Read more](https://daily.dev/posts/Y12VjTTqY) - **KurrentDB 26.2 moves clustering behind an Enterprise license, frees 21 other features:** Starting with KurrentDB 26.2 (targeting Q3/Q4 2026), multi-node clustering, read-only replicas, archiving, and encryption at rest require an Enterprise license, while connectors, OAuth/LDAP, OpenTelemetry, and the Kubernetes Operator become free; single-node production deployments stay fully free. [Read more](https://daily.dev/posts/s0VCosGaG) - **Continuous batching gets vLLM to 23x the throughput of naive HF serving:** Anyscale's benchmark on OPT-13B showed vLLM's continuous batching scheduler hitting 23x the throughput of naive Hugging Face serving on the same A100, while static batching collapsed to around 81 tokens/s under varied output lengths. [Read more](https://daily.dev/posts/YrZPpfM2W) - **DeepSeek silently swaps V4 Pro weights on the same endpoint, breaking tool calls:** DeepSeek replaced the preview build behind deepseek-v4-pro with the officially released V4 Pro 0813 without changing the endpoint name or schema, so instruction-following and tool-call JSON formatting shifted unexpectedly for anyone not pinning to dated model aliases. [Read more](https://daily.dev/posts/5a1iFAlq2) - **Cerbos PDP v0.55.0 adds strict evaluation mode to stop silent policy denials from leaking access:** The new opt-in mode turns runtime errors in policy conditions into explicit denials instead of silently skipping the rule, closing a gap where a broken DENY rule could quietly widen access, alongside multi-JWT support and a CEL upgrade adding 21 new functions. [Read more](https://daily.dev/posts/fwnpiG9p8) --- Tags: [#ai-agents](https://daily.dev/tags/ai-agents), [#infrastructure](https://daily.dev/tags/infrastructure), [#docker](https://daily.dev/tags/docker), [#rails](https://daily.dev/tags/rails), [#recommendation-systems](https://daily.dev/tags/recommendation-systems) [View this post on daily.dev](https://daily.dev/posts/docker-builds-its-own-vm-engine-x-open-sources-its-ranking-algorithm-keuat9ig5) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"DiscussionForumPosting","mainEntityOfPage":"https://daily.dev/posts/docker-builds-its-own-vm-engine-x-open-sources-its-ranking-algorithm-keuat9ig5","headline":"Docker builds its own VM engine, X open-sources its ranking algorithm","text":"Docker Desktop 4.86 ships Docker VMM, a self-built virtualization layer replacing the patchwork of libkrun, Hyper-V, and KVM across platforms. 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