BuildKit vs Earthly

BuildKit is a free toolkit for turning source code into build artifacts. It consists of the buildkitd daemon and buildctl client, and uses LLB, a binary format for describing process dependency graphs. Builds can use Dockerfiles or other LLB-compatible frontends, resolve dependencies concurrently, cache instructions, import and export caches, run nested jobs, and collect unused data automatically. BuildKit supports execution without root privileges and OCI (runc) or containerd workers. Results can be exported as images, local directories, tarballs, Docker tarballs, or OCI tarballs. Cache options include inline, registry, local-directory, and GitHub Actions backends; the README marks GitHub Actions, S3, and Azure Blob options experimental. The daemon provides a gRPC API over a Unix socket by default, with TCP sockets also supported. Binaries are available for Linux, macOS, and Windows. The unofficial Homebrew formula for macOS omits buildkitd; the project gives Lima in a Linux virtual machine as one way to run it. BuildKit is licensed under Apache-2.0.

Earthly Lunar monitors software development activity and applies engineering policies across developer and AI workflows. It collects structured metadata from source repositories and CI/CD pipelines, then evaluates it against policies an organization defines. Lunar can be added to existing CI/CD pipelines without YAML changes or wholesale pipeline rewrites. Its guardrails can run while code is authored, on pull requests, and at deployment gates; enforcement can progress from draft and scoring to comments or blocking pull requests and deployments. Earthly lists more than 200 prebuilt guardrails for testing, security, compliance, and operational readiness. The integrations page lists 66 integrations, with Bash-script options for custom collectors and catalogers. Documentation includes a SQL API for engineering data and a CI agent that can run on self-hosted runners and is compatible with major CI vendors. Earthly says its services and databases are hosted on AWS in the United States, data is encrypted at rest and in transit, and it has SOC 2 Type II compliance. Earthfiles, an open-source portable build syntax, remains available. Earthly says the company was founded in 2020 and Lunar launched in 2026.