KoalaSync
Thriving Thriving JavaScript JS HTML HT
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KoalaSync Shik3i/KoalaSync

Minimalist, privacy-first synchronized video playback for YouTube, Netflix, Emby, and general HTML5. Built with pure Vanilla JS and a Node.js relay.

https://sync.koalastuff.net ↗
HEALTH 100 / Healthy
// hidden gem// funded// release machine chrome-extensionvideo-syncprivacy-firstsocket-iovideo-synchronizationwatch-partywebsocketembyfirefox-addonjellyfin
04-2026 · today · Shik3i
★20 Share View on GitHub ↗

// readme

KoalaSync

🌟 Why KoalaSync?

  • 🛡️ Security-First: Volatile RAM-based relay with built-in brute-force protection and zero-persistence architecture. We keep no logs of your sessions or synchronizations. We don’t track you. We only track our server (relying on the aggregated, anonymous, non-personal metrics provided under /health).
  • 📡 Direct Logic: Manual Socket.IO wire implementation for reliable synchronization.
  • 🛠️ Clean Build: Dependency-free extension runtime with no library overhead.
  • 🌐 Universal: Works on any website with a <video> tag.

✨ Key Features

  • Global Synchronization: Synchronize Play, Pause, and Seeking on any website with a <video> tag.
  • Episode Auto-Sync: Perfectly sync series binges. All peers wait until everyone has loaded the next episode before starting together.
  • Smart Matching: Automatically highlights tabs containing matching video titles.
  • Dual Heartbeat Architecture: Robust session tracking that prevents ghost rooms and stale connections.
  • Efficient Relay: Minimal overhead WebSocket message…
↑ The Undervalued Score +

How much a project earns versus how much attention it actually gets. Above 50 means the work is outrunning its audience. Recomputed nightly from commit velocity, contributor effort, issue resolution, fork utility, release cadence, and project maturity — divided by a logarithmic reach factor.

score  = signal / reach

signal = 0.25·commit_velocity   // commits in last 90 days (cap 30)
       + 0.20·contributor_work  // unique authors × velocity (cap 100)
       + 0.20·issue_resolution  // closed ÷ total issues
       + 0.20·fork_ratio        // forks ÷ stars (proxy for real usage)
       + 0.10·release_cadence   // releases in 90 days (cap 3)
       + age_bonus              // +0 to +0.30 after 6 months
       + homepage_bonus         // +0.05 if homepage is set

reach  = log₁₀(stars + watchers + 10)█
♥ The Health Score +

Is the project alive and maintained right now? A 0–100 pulse recomputed nightly from commit recency, rhythm, how fast issues close, and how quickly PRs get merged.

health = 0.35·recency       // days since last commit (90d decay)
       + 0.25·cadence       // commit rhythm consistency
       + 0.20·issue_health  // closed ÷ total issues
       + 0.20·pr_health     // merged ÷ total PRs█
◷ Health bands +

The colour and label on every card come straight from the health score.

Healthy   80 – 100   active, responsive, regular releases
Stable    60 – 79    maintained, steady, no alarms
Quiet     40 – 59    slowing down — watch this one
At Risk    0 – 39    going dark · candidate for rescue█
// Tags — what each label means +

Tags are independent behavioral signals computed nightly. A project can hold multiple at once. They drive the home page sections.

solo_builder      one person holds > 80% of commits (last 180d)
needs_contributors has open "help wanted" or "good first issue" labels
hidden_gem        < 100 stars · active in last 3 months · documented
legacy_hero       repo > 5 years old · committed this year
fork_magnet       forks/stars > 0.5 · used as template or dependency
release_machine   5+ releases in the last 90 days
under_pressure    > 10 open issues · ≤ 2 contributors · health ≥ 60
community_watch   watchers > stars · devs tracking before the public
community_hub     GitHub Discussions enabled · > 20 discussions
funded            maintainer has active funding channel█
★ Why rank against stars at all? +

Stars are an outcome, not effort. A project with 8 stars and daily commits is doing more interesting work than one coasting on 8k. We measure the building, then divide by the attention already received — so the genuinely undervalued rise to the top.

// stars   = lagging indicator
// commits = leading indicator
// we rank by the leading one█