// the find
microsoft/FluidFramework
Library for building distributed, real-time collaborative web applications
Fluid Framework is Microsoft's CRDT-based library for building real-time collaborative web apps — think Google Docs-style multiplayer on top of your own data model. It ships the client SDK, a reference ordering service (Routerlicious), and a local dev server (Tinylicious), so you can run the whole stack yourself. The primary audience is teams building collaboration features into web products who want something more principled than operational transforms.
The CRDT model is genuinely well-thought-out: shared data structures like SharedMap, SharedString, and the newer SharedTree give you composable, conflict-free primitives rather than forcing you to bolt OT onto an existing model. The monorepo tooling is unusually mature for an open-source project — fluid-build, layer-check, and the automated API extraction pipeline show real investment in keeping a large package graph honest. SharedTree in particular is a meaningful step up from the v1 DDS model: it handles deeply nested, typed tree structures with schema enforcement, which is what almost every real collaborative app actually needs. The compatibility story is explicit and versioned, with separate release groups and formal API stability tiers (public/beta/alpha) — you know exactly what you're signing up for.
The operational complexity of running this in production is brutal: you need a real Fluid ordering service (Azure Fluid Relay, or self-hosted Routerlicious with its Kafka/Redis/MongoDB dependencies), and the self-hosted path is underdocumented and clearly not the happy path. The build setup is also a significant onboarding tax — pnpm workspaces, node-gyp native addons, Git LFS submodules for test data, and a bespoke build tool chain mean a fresh contributor can spend half a day just getting `pnpm build` to succeed. The 4,900-star count is low for a Microsoft project of this age, which reflects real adoption friction — most teams end up locked to Azure Fluid Relay, which defeats the 'open' part of open source. SharedTree's API surface is still churning; if you touch anything outside the stable tier you're signing up for breaking changes on minor releases.