CI/CD

4 open source tools compared. Sorted by stars — scroll down for our analysis.

Tool	Stars	Velocity	Language	License	Score
Jenkins The original CI/CD automation server	25.2k	+28/wk	Java	MIT License	79
ArgoCD Declarative continuous deployment for Kubernetes	22.5k	+37/wk	Go	Apache License 2.0	79
Dagger Automation engine to build, test, and ship any codebase	15.6k	+32/wk	Go	Apache License 2.0	77
Woodpecker Simple yet powerful CI/CD engine	6.8k	+36/wk	Go	Apache License 2.0	73

Our Analysis

Jenkins25.2k★

Jenkins automates builds, tests, and deployments with 1,800+ plugins covering virtually every tool in the software development ecosystem. Jenkins is the original and still the most extensible. It's been around since 2011 and there isn't a workflow it can't handle. MIT licensed. Jenkins runs builds, tests, and deployments using declarative or scripted pipelines defined in Jenkinsfiles. It scales from a single machine to hundreds of build agents. Fully free. No paid tier. CloudBees offers a commercial Jenkins distribution, but the community edition is complete. The catch: Jenkins is showing its age. The UI looks like 2012. Configuration is often click-through rather than code-first. Maintaining a Jenkins server means updating plugins constantly (some of which conflict), managing security patches, and dealing with Java memory tuning. Modern alternatives like GitHub Actions, GitLab CI, or ArgoCD handle common workflows with less operational burden. Jenkins still wins for complex, custom pipelines that nothing else can express, but if your needs are standard, you're paying an ops tax for flexibility you don't use.

ArgoCD22.5k★

ArgoCD watches your Git repo and automatically syncs what's deployed in Kubernetes to match what's committed, making Git the single source of truth for your infrastructure. Push a change to Git, ArgoCD deploys it. Someone manually edits the cluster, ArgoCD reverts it. That's GitOps. Apache 2.0, CNCF graduated project. The UI shows you a live dependency graph of every resource in your app, color-coded by sync status. You can see at a glance what's deployed, what's out of sync, and what's degraded. Fully free. No paid tier from the Argo project. Akuity (founded by Argo creators) offers a managed version starting at $0 for small clusters, scaling with usage. ArgoCD handles multi-cluster deployments, Helm charts, Kustomize overlays, plain YAML, and Jsonnet. RBAC is built in. SSO works via OIDC/SAML. The catch: ArgoCD itself needs to run somewhere, and it's not lightweight. The controller, server, repo server, and Redis consume real resources. Initial setup for a production-grade deployment (HA mode, SSO, RBAC policies) takes days, not hours. And the application-of-applications pattern for managing many apps has a learning curve.

Dagger15.6k★

Daily.dev aggregates developer news from hundreds of tech blogs, GitHub trending, and community submissions into a personalized feed. You define build steps as functions, run them locally on your machine, and the same pipeline runs identically in any CI system (GitHub Actions, GitLab, Jenkins, whatever). Apache 2.0, Go. The core idea: pipelines are code, not config files. Everything runs in containers, so "works on my machine" actually means something. You can test your entire CI pipeline locally before pushing. The SDK gives you type-safe build steps with autocomplete in your editor. The open source engine is fully free. Write pipelines, run them locally, run them in any CI, no cost. Dagger Cloud adds caching, pipeline visualization, and debugging tools. There's a free tier. Paid plans haven't been publicly detailed with fixed prices yet, but the cloud offering is where the business model lives. Solo devs: free tier is plenty. Local execution is the killer feature. Small teams: free engine plus Dagger Cloud free tier for shared caching. Medium to large: evaluate Dagger Cloud paid for team-wide cache and observability. The catch: you're adding a layer of abstraction on top of your CI. If your YAML pipelines work fine and your team knows them, the migration cost is real. And while "write CI in TypeScript" sounds great, you're now debugging TypeScript instead of YAML. The complexity moved, it didn't disappear.

Woodpecker6.8k★

Woodpecker is a self-hosted CI engine that's dead simple to set up. It's a community fork of Drone CI, after Drone went commercial. Apache 2.0, Go. The YAML pipeline syntax is nearly identical to Drone's. Docker-based execution means each step runs in an isolated container. Supports GitHub, GitLab, Gitea, Forgejo, and Bitbucket. Multi-platform: Linux, ARM, Windows agents. Fully free. No paid tier, no premium features, no hosted offering. Everything (parallel pipelines, matrix builds, secrets management, cron jobs) is included. Self-hosting is straightforward. One server + one or more agents. A small VPS ($5-10/mo) handles most projects. Docker Compose gets you running in under 15 minutes. The ops burden is light. It's a Go binary, not a Java monstrosity. Solo to small teams: perfect. You get unlimited CI minutes for the cost of a cheap VPS. Medium teams: works well with multiple agents for parallel builds. Large teams: possible, but you'll miss the plugin ecosystem and enterprise features that Jenkins or GitLab CI offer. The catch: the plugin ecosystem is smaller than Drone's was, and vastly smaller than GitHub Actions or GitLab CI. If you need a niche integration, you might be writing your own. And the community, while active, is small. Fewer tutorials and Stack Overflow answers.