Open Source Mindset

Tweag's goal is to democratize state-of-the-art technologies by promoting or developing new open-source frameworks, programming languages, and tools.

We strive to improve developer experience (DX) and data-centric workflows (MLOps). Our engineers are the creators of Nickel, a generic configuration language, and among the top contributors to Nix, Haskell, and Bazel.

We execute the open-source mindset by taking a community-centric approach, addressing bottlenecks to community growth, and engaging in its governance.

Matching the Software Development Lifecycle

We bring together incredibly talented engineers, who are well respected within their communities of practice to contribute something interesting and novel to each step in the SDLC. Alongside the track record of our consulting organization, that means we bring unparalleled skill to your most pressing challenges.

Nix

Many thought leaders of the Nix community are Tweagers. Together with our clients, we contribute much of the technical roadmap, from better reproducibility and performance to new use cases and developer tools.

Nickel

Better configuration for less

Write complex configurations. Modular, correct and boilerplate-free.

Ormolu

A formatter for Haskell source code

Ormolu is a formatter for Haskell source code.

rules_haskell

Haskell rules for Bazel

Bazel automates building and testing software. It scales to very large multi-language projects. This project extends Bazel with build rules for Haskell. Get started building your own project using these rules with the setup script below.

Topiary

The universal code formatter

Rust, Tree-sitter

Topiary is a tool in the Tree-sitter ecosystem, designed for formatter authors and formatter users. Authors can create a formatter without having to write their own engine or even their own parser.

Bazel

We were among the first outside of Google to adopt Bazel. We are recognized community experts. We have contributed key features and new programming language support to Bazel. We did this for ourselves and now we can do it for you.

Haskell

We are among the top contributors to GHC, a mature, state-of-the-art compiler for Haskell. Choosing Haskell is a path to more correct, scalable code for industries where mistakes matter. We created language interop with Java, JavaScript, C and R, we make Haskell run in your browser, and do the heavy lifting in your analytics pipelines.

FawltyDeps

Python dependency checker

FawltyDeps is a dependency checker for Python that finds undeclared and/or unused 3rd-party dependencies in your Python project. The name is inspired by the Monty Python-adjacent Fawlty Towers sitcom.

opam-nix

Turn opam-based OCaml projects into Nix derivations

Turn opam-based OCaml projects into Nix derivations, automatically resolving both OCaml and system dependencies.

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Discover the rest of our projects