Copyleft (GPL, AGPL, MPL) developer tools

• GrafanaDashboards for everything observable

  Free / OSS · AGPL-3.0 · 77.4k GitHub stars

  VerdictThe universal observability dashboard.

  CatchDashboard sprawl becomes a maintenance burden. Learning PromQL or LogQL takes time. Self-hosting requires infrastructure.

• LogtoMPL-2.0 identity platform with a 50k-MAU free Cloud

  Free / OSS · Freemium · 14.7k GitHub stars

  VerdictThe MPL-2.0 Auth0-shaped stack. Use it when Clerk MAUs are the product.

  CatchCloud Free is for starting out. Passkeys, hiding branding, orgs, MFA, and enterprise SSO live as Pro add-ons. MPL-2.0 is file-level copyleft, not MIT.

• ListmonkAGPL-3.0 self-hosted newsletters and transactional mail

  Free / OSS · AGPL-3.0 · 23.8k GitHub stars

  VerdictThe self-host newsletter stack. AGPL, fully free, you run the mail.

  CatchAGPL-3.0 is copyleft — network use means you share modifications. You operate Postgres, SMTP, and bounces. There is no official hosted Listmonk Cloud.

• ZedGPL-3.0 GPU-accelerated editor with first-party agents

  Free / OSS · GPL-3.0 · 91.9k GitHub stars

  VerdictThe fast open editor. GPL-3.0, agents in-process, no invented Cloud giveaway.

  CatchGPL-3.0 is copyleft, not MIT. Hosted agent features that talk to Zed's models are a product on top of the editor — no Cloud free tier to count on. Web is not shipped.

• LagoAGPLv3 usage and entitlements metering you self-host

  Free / OSS · AGPL-3.0 · 10.7k GitHub stars

  VerdictAGPLv3 metering. Self-host or talk to sales — there is no hobby cloud.

  CatchPremium is Contact us. There is no $0 Lago Cloud. Self-host is the free path; Cloud and Premium are quotes. AGPLv3 is network copyleft.

• PlunkAGPL-3.0 transactional email, workflows, and broadcasts

  Free / OSS · Freemium · 5.5k GitHub stars

  VerdictAGPL email with a real 1k hosted free tier. Branding stays until you pay.

  CatchAGPL-3.0 is copyleft. Hosted Free keeps Plunk branding. This is not Resend at volume — 1k/mo is the free wall, then $0.001/email. Self-host means you bring SES or equivalent.

• ZITADELAGPLv3 identity Cloud at US$0/Month — 100 DAU, not Logto 50k MAU

  Free / OSS · Freemium · 15.3k GitHub stars

  VerdictAGPL identity with a real $0 Cloud. 100 DAU is the meter; self-host if that is a joke.

  Catchthe wall is 100 DAU, not Logto 50k MAU. AGPLv3 is network copyleft — Cloud or self-host, the license is loud. Pro is US$100/Month for 25k DAU. Distinct from Hanko passkeys-first Cloud and authentik no-hosted-hatch.

• OpenMeterApache-2.0 usage-event metering; Cloud is Kong Konnect now

  Free / OSS · AGPL-3.0 · 2.4k GitHub stars

  VerdictApache-2.0 metering you compose locally. Hosted path is Kong; README is beta.

  CatchCloud is now Kong Konnect Metering — check current Kong pricing on the vendor site. Distinct from Lago: usage-event metering first, not AGPL usage-billing with no hobby cloud. Compose is a local evaluation stack (Kafka/ClickHouse), not production topology.

• MercureAGPL-3.0 SSE hub; homepage still says MIT

  Free / OSS · AGPL-3.0 · 5.3k GitHub stars

  VerdictAGPL SSE hub. Believe the LICENSE file, not the MIT line on the homepage.

  CatchHomepage still says the Hub is MIT-licensed. The LICENSE file is AGPL-3.0 — print the file. SSE, not WebSockets, not Pusher protocol. Distinct from Socket.IO and Soketi. Cloud/Enterprise exist; check their pricing page. OSS self-host is the free path.

• KanidmMPL-2.0 Rust IdP aiming to replace needing Keycloak

  Free / OSS · Apache-2.0 · 5.5k GitHub stars

  VerdictMPL-2.0 Rust IdP. Self-host free. Not Keycloak.

  CatchRust IdP aiming to replace needing Keycloak — not the Java CNCF suite. Distinct from Keycloak (Apache-2.0 JVM IAM). You still operate the box.

• InvoiceShelfAGPL-3.0 self-host invoices, estimates, expenses, client portal

  Free / OSS · AGPL-3.0 · 1.9k GitHub stars

  VerdictAGPL SMB invoicing you host. Free forever; not a metering engine.

  CatchSMB invoices/estimates/expenses/portal + Stripe on your server — not Kill Bill/Lago subscription orchestration or usage metering. Crater cut re-opened as InvoiceShelf. Distinct from Kill Bill and Lago.

• MauticGPL-3.0 self-host marketing automation; hosted trial is not free

  Free / OSS · GPL-3.0 · 10.8k GitHub stars

  VerdictGPL-3.0 marketing automation. Self-host free; hosted trial is not forever-$0.

  CatchMarketing automation — not Listmonk newsletter/tx alone. Hosted 14-day trial is NOT the free path; self-host is. Distinct from Listmonk.

• Janus GatewayGPL-3.0 plugin-core WebRTC gateway (SIP, VideoRoom, streaming)

  Free / OSS · GPL-3.0 · 9.2k GitHub stars

  VerdictGPL-3.0 WebRTC gateway. Self-host free; commercial options exist — pitch the OSS core.

  CatchPlugin-core C gateway — not LiveKit/mediasoup opinionated rooms products. You pick plugins and ops the gateway. Distinct from LiveKit, mediasoup, PeerJS, and Pion.

• EdgepushAGPL server + MIT SDK: BYO APNs/FCM on Cloudflare Workers

  Free / OSS · Freemium · 9 GitHub stars

  VerdictAGPL Workers push. Self-host $0; Hosted Free is capped — ignore Pro.

  CatchBYO APNs+FCM on Cloudflare Workers — not ntfy/Gotify self-host pub/sub, not Novu workflow orchestration. Server is AGPL; pitch self-host or Hosted Free caps. Distinct from ntfy, Gotify, and Novu.

• ShoveMIT end-to-end Go device-push relay

  Free / OSS · AGPL-3.0 · 283 GitHub stars

  VerdictMIT Go push relay. Self-host free; not Edgepush AGPL Workers.

  CatchEdgepush server is AGPL; Shove is MIT end-to-end Go. Device-push relay — not ntfy/Gotify general pub/sub, not Novu multi-channel workflows. Distinct from Edgepush, ntfy, Gotify, and Novu.

• Hyvor RelayAGPL-3.0 email relay; Self-Hosted Free Forever unlimited

  Free / OSS · AGPL-3.0 · 918 GitHub stars

  VerdictAGPL email relay. Self-host free forever; no Cloud free claim.

  CatchCloud is not free. Self-host unlimited is the pitch. Vs Postal full mail server and Plunk Node email. Distinct from Postal and Plunk.

• UnleashAGPLv3 feature flags; OSS caps 1 project / 2 environments

  Free / OSS · AGPL-3.0 · 13.9k GitHub stars

  VerdictAGPLv3 flags. Self-host with OSS caps; Cloud trial is not free forever.

  CatchOSS caps Projects 1 / Environments 2. Cloud = Enterprise trial FAIL — pitch self-host only. Vs PostHog dedicated-flags-inside-analytics. Distinct from PostHog.

• ParadeDBAGPL-3.0 Postgres search + analytics; Community free forever

  Free / OSS · AGPL-3.0 · 9.4k GitHub stars

  VerdictAGPL Postgres search. Community self-host free forever. Cloud is not the free path.

  CatchSearch + analytics inside Postgres (pg_search) — not a separate search server. Distinct from Typesense/Meilisearch (cut: no free forever Cloud). Cloud is waitlist/beta — NOT a free hosted tier. Enterprise HA is sales; check current Enterprise pricing on the vendor site.

• GarageAGPL-3.0 S3-compatible store for small geo-distributed hosts

  Free / OSS · AGPL-3.0 · 4.7k GitHub stars

  VerdictAGPL S3 for small clusters. Self-host free. Not MinIO-scale.

  CatchAGPL. S3-compatible for small/geo-distributed self-host — not SeaweedFS/Ceph/MinIO-scale. SeaweedFS omitted once this publishes. Stretch: object store outside core remit, kept for the free forever self-host bar.

• OpenBaoMPL-2.0 Vault-compatible secrets engine after the Vault fork

  Free / OSS · MPL-2.0 · 8.5k GitHub stars

  VerdictMPL Vault-compat engine. Fork for license, not Infisical DX.

  CatchVault-engine / IdP-secrets lane, not Infisical app-secrets DX. This is the engine/compat fork, not the developer-secrets UI. Don’t assume a Cloud free tier.

• SockudoMIT Rust Pusher V1 edge + Protocol V2 recovery/history/push

  Free / OSS · AGPL-3.0 · 828 GitHub stars

  VerdictMIT Rust Pusher-compat with V2 durability. Not AGPL Soketi.

  CatchVs Soketi: Rust Pusher V1 edge + Protocol V2 recovery/history/mutable/push — not AGPL v7-only. Distinct from Soketi AGPL Protocol v7 drop-in. Self-host is the free path.

• TinyauthAGPL-3.0 one-binary proxy auth + Certified OIDC

  Free / OSS · AGPL-3.0 · 8.4k GitHub stars

  VerdictAGPL one-binary proxy auth + Certified OIDC. Self-host forever.

  CatchVs Authelia/Pocket ID: tiny proxy-fronted auth + Certified OIDC in one binary — not Authelia reverse-proxy SSO alone, not passkeys-only Pocket ID. Free path is self-host.

• OpenTofuMPL-2.0 Linux Foundation Terraform fork; truly OSS IaC

  Free / OSS · MPL-2.0 · 30.5k GitHub stars

  VerdictMPL-2.0 Terraform-compatible IaC. The OSS license answer to BSL.

  CatchVs Terraform/Pulumi: license-first fork of Terraform 1.5-era lineage — not Pulumi programming-language IaC. Not HashiCorp Cloud/Enterprise features. Provider edge cases exist; verify before big migrations.

• PenpotMPL-2.0 Figma-class design; self-host forever + Cloud Professional $0

  Free / OSS · Freemium · 61.3k GitHub stars

  VerdictMPL-2.0 design suite. Self-host free; Cloud Pro $0 then Unlimited ~$7/editor.

  CatchOnly serious OSS Figma-class design; not Excalidraw whiteboards. Cloud Unlimited from ~$7/editor (capped ~$175/mo). Self-host means you own Docker/backups/upgrades. Ecosystem/plugins thinner than Figma marketplace.

• HelixMPL-2.0 modal terminal editor — tree-sitter + LSP

  Free / OSS · MPL-2.0 · 46.6k GitHub stars

  VerdictMPL-2.0 terminal editor. Free forever; not Zed/Cursor.

  CatchVs Zed: terminal modal + tree-sitter/LSP; not a GPU IDE. No Electron GUI, weaker AI-IDE surface than Cursor/Zed. Plugin story is thinner than Neovim.

• TypesenseGPL-3.0 typo-tolerant search; Cloud managed paid

  Free / OSS · Freemium · 27k GitHub stars

  VerdictGPL-3.0 search. Self-host if you accept copyleft; Cloud is paid.

  CatchGPL-3.0 copyleft — distributing modified Typesense (or a SaaS that conveys it) pulls GPL obligations; not MIT like Meilisearch CE. Cloud paid ≠ forever free. Distinct from Meilisearch MIT CE and ParadeDB Postgres search.

• VectorMPL-2.0 logs/metrics/traces data plane vs OTel Collector/Alloy

  Free / OSS · MPL-2.0 · 22.7k GitHub stars

  VerdictMPL-2.0 obs data plane. Free to run; watch MPL + Datadog stewardship.

  CatchMPL-2.0 (file-level copyleft, not MIT/Apache). Datadog-maintained after Timber acquisition - product direction follows Datadog. Distinct from OpenTelemetry Collector and Grafana Alloy.

• PushForgeMIT edge-native Web Push builder; free playground

  Free / OSS · AGPL-3.0 · 66 GitHub stars

  VerdictMIT edge Web Push lib. Free forever library + playground; you own the delivery stack.

  CatchVs Edgepush, Shove, ntfy, Gotify, and Novu: edge Web Push HTTP builder — not a Workers device-push product, not a Go APNs/FCM relay, not self-host pub/sub, not multi-channel workflows. You still implement the service worker, subscription store, and send loop yourself.

• SOPSMPL-2.0 encrypts config values; keys stay readable

  Free / OSS · MPL-2.0 · 23.4k GitHub stars

  VerdictMPL-2.0 secrets-in-git. Free forever; use age underneath when you want KMS-free recipients.

  CatchVs age (file encryption) and Infisical (secrets product): SOPS is the *structured config encryptor*, not a password manager and not a hosted vault UI. You still design key distribution, rotation, and who can decrypt in CI. Binary mode encrypts whole files when structure does not apply.

• SemgrepLGPL-2.1 SAST engine; Free Edition caps repos/contributors

  Free / OSS · LGPL-2.1 · 17.1k GitHub stars

  VerdictLGPL SAST. Free forever CLI; Free Edition SaaS for small teams; Teams when AppSec wants the paid platform.

  CatchVs Trivy/Gitleaks (scanners): Semgrep is SAST/SCA-shaped AppSec, not container CVE inventory or git-history secret regex alone. Teams starts ~$30/contributor/mo per product; Secrets is a separate SKU. Free Edition caps contributors/repos — OSS CLI without the SaaS seat is the uncapped escape hatch.

More with this tag (56)

• D2 — MPL-2.0 diagram-as-code; TALA bundled for auto-layout
• Lightning CSS — MPL-2.0 CSS parser, transformer, and minifier in Rust
• eza — EUPL-1.2 modern ls replacement in Rust (exa successor)
• doggo — GPL-3.0 human DNS client — DoH/DoT/DoQ/DNSCrypt + web UI
• k6 — AGPL-3.0 scriptable load testing (JS) from Grafana
• ShellCheck — GPL-3.0 de-facto static analysis for shell scripts
• Hadolint — GPL-3.0 AST Dockerfile linter + ShellCheck on RUN
• River — MPL-2.0 durable Postgres job queue for Go; Pro is paid add-ons
• Open Interpreter — Apache-2.0 terminal coding agent; Rust Codex fork for open models
• RustFS — Apache-2.0 Rust S3-compatible object store
• BrewUI — AGPL-3.0 official Homebrew macOS GUI
• Firecrawl — AGPL-3.0 OSS + cloud scrape API — LLM-ready pages
• OpenStatus — AGPL-3.0 status/uptime as code — Terraform/CLI/MCP
• Tinycast — Native macOS launcher — hotkeys, clipboard, Raycast extensions, under 100 MB RAM
• Hister — Private local search over visited pages and files
• Coder — Durable remote workspaces for humans and coding agents
• Cua — Open computer-use drivers, sandboxes, MCP, and CUA-S1 decision models
• OpenViking — AGPL self-evolving context database for memory, RAG, and skills
• Paperless-ngx — GPL-3 document management — scan, OCR, tag, and full-text search
• OpenHuman — GPL-3 local-first agent orchestrator with memory trees and MCP
• LitterBox — Malware and payload detection sandbox with LitterBoxMCP
• Equibles — Self-hosted financial-data MCP — SEC, 13F, FRED, prices for agents
• Workflow Use — AGPL RPA 2.0 — record/run durable browser workflows
• BrowserOS — AGPL agentic browser — open alternative to Atlas/Comet/Dia
• Invisible Playwright MCP — MIT stealth Firefox Playwright MCP — not plain Chromium MCP
• git-bug — GPL-3.0+ offline-first bugs stored inside the git repo
• OpenKnowledge — GPL-3.0 local markdown IDE + LLM wiki — MCP/skills for agent editing
• cmux — Native macOS terminal for parallel coding agents
• TruffleHog — AGPL-3.0 secret scanner that finds leaked credentials and checks whether they still work
• Codync — Apache-2.0 bots for Claude Code, Codex, Cursor and 40+ ACP agents — message them from phone or desktop
• Kandev — AGPL-3.0 multi-agent kanban with git worktrees — orchestrate, review diffs, open PRs
• Firecrawl MCP Server — MIT official MCP server for Firecrawl scraping
• Nginx UI — AGPL-3.0 web UI for managing Nginx configs, certs and logs
• Unsloth — Apache-2.0 core for fast local LLM fine-tuning, plus an AGPL desktop studio
• Homepage — GPL-3.0 dashboard with 100+ service widgets
• Glance — AGPL-3.0 lightweight self-hosted feed dashboard
• Backrest — GPL-3.0 web UI and scheduler for restic backups
• Komodo — GPL-3.0 build and deploy tool for Docker across many servers
• Technitium DNS Server — GPL-3.0 self-hosted recursive DNS server
• ByteStash — GPL-3.0 self-hosted code snippet manager with MCP
• Sonic — MPL-2.0 tiny Rust search backend, an Elasticsearch-lite
• Citus — AGPL-3.0 Postgres extension for distributed tables
• drawDB — AGPL-3.0 browser ER diagram editor and SQL generator
• Grafana Pyroscope — AGPL-3.0 continuous profiling platform
• Grafana Mimir — AGPL-3.0 scalable long-term Prometheus storage
• Uptrace — AGPL-3.0 OpenTelemetry APM on ClickHouse and Postgres
• Parseable — AGPL-3.0 observability data lake in a single binary
• lldap — GPL-3.0 light LDAP server for simple user management
• Meteroid — AGPL-3.0 usage-based pricing and billing platform
• Bigcapital — AGPL-3.0 self-hosted accounting and inventory app
• Artillery — MPL-2.0 load testing for HTTP, WebSockets and browsers
• VisiData — GPL-3.0 terminal spreadsheet for exploring tabular data
• ComfyUI — GPL-3.0 node-graph engine and API for local image, video and audio models
• ToolJet — AGPL-3.0 low-code builder for internal tools on your own data
• Agent-MCP — AGPL MCP-native multi-agent + shared knowledge graph
• Smithery — Freemium MCP registry, gateway, and hosting marketplace