A Glimpse into Unison

I recently came across Unison — a programming language and platform that promises some deep shifts in how code is written, stored, and reused. It’s an experimental take on many ideas I’ve bumped into separately over the years — functional programming, content-addressing, immutable data, distributed systems — brought together in a focused and practical way.

The basic idea is compelling: every definition in Unison is content-addressed by its syntax tree. Instead of a file full of lines of text, you’re working with a semantic structure that the language runtime knows how to interpret, share, and version — all by hash. This isn’t just an implementation detail. It’s central to how code is managed, deployed, and reasoned about.

Code as Content: A Shift in Perspective

What Unison does with code is similar to what IPFS or Git do with files. If a chunk of data is the same, it gets the same address. No need to track changes manually or rely on directory structures. If a function or type hasn’t changed, it doesn’t need to be recompiled or redeployed — it just lives at the same hash.

This is a big shift from the way programming has traditionally worked. Most languages live in a Von Neumann-style setup where code and data are stored separately but can act on each other. That allows bytecode or machine code to behave as a kind of dynamic instruction set — load something from disk, parse it, run it. But it’s messy. There’s lots of glue: build systems, CI pipelines, deployment scripts, version conflicts.

Unison trims that mess down by making the codebase itself append-only and automatically structured. When you define a function, its identity is based on its structure — not its location or version number. This could dramatically simplify things like dependency management, reproducibility, or collaborative coding.

Parallel Inspiration: IPFS, Git, and Functional Programming

The approach echoes ideas from other content-addressed systems. IPFS (InterPlanetary File System) applies content-based addressing to general storage: if a file has the same contents, it gets the same hash, no matter who stores it or when.

Git, too, uses hashes to track commits and snapshots of code, making versioning predictable and verifiable.

Unison is taking that core idea and layering it on top of a functional programming model. Immutability becomes the default. Refactoring becomes safer. There’s less concern about side effects or dependencies leaking across modules.

Unstructured Curiosity

My current understanding is still at the surface. I’ve browsed the docs, watched a few demo videos, and tried to wrap my head around the Unison Cloud model. There’s a sense that this is still in motion — not just a finished product, but a growing experiment with its own ecosystem and learning curve.

One resource that stood out is the Unison Microblogging Series — a short-form, progressive introduction to the platform and its ideas. It breaks things down without getting too formal and feels like a good place to start.

I’m keen to keep exploring and understand it more deeply.