[opensourcedex]

best-of ranking · updated nightly

Best Open Source Marketing & Customer Engagement Tools

Ranked by GitHub stars — actual adoption, not editorial taste. All 10 are free, open source and self-hostable; license and last activity on every entry.

  1. 1
    duckdb ★ 41K

    DuckDB is an analytical in-process SQL database management system

    MIT C++ pushed 2026-09-17 details →
  2. 2
    Krayin ★ 24K

    Self-hosted CRM for enhanced business relationships

    MIT PHP pushed 2026-09-14 details →
  3. 3
    Listmonk ★ 23K

    Self-hosted newsletter and mailing list manager

    AGPL-3.0 Go pushed 2026-09-13 details →
  4. 4
    goaccess ★ 21K

    GoAccess is a real-time web log analyzer and interactive viewer that runs in a terminal in *nix systems or through your browser.

    MIT C pushed 2026-09-16 details →
  5. 5
    excelize ★ 21K

    Go language library for reading and writing Microsoft Excel™ (XLAM / XLSM / XLSX / XLTM / XLTX) spreadsheets

    BSD-3-Clause Go pushed 2026-09-16 details →
  6. 6
    claude-seo ★ 17K

    Universal SEO skill for Claude Code. 25 sub-skills + 18 sub-agents covering technical SEO, E-E-A-T, schema, GEO/AEO, backlinks, local SEO, maps intelligence, se

    MIT Python pushed 2026-09-11 details →
  7. 7
    Billion Mail ★ 16K

    Open-source mail server with unlimited sending & AI tools

    AGPL-3.0 Go pushed 2026-06-11 details →
  8. 8
    BillionMail ★ 16K

    BillionMail gives you open-source MailServer, NewsLetter, Email Marketing — fully self-hosted, dev-friendly, and free from monthly fees. Join the discord: http

    AGPL-3.0 Go pushed 2026-06-11 details →
  9. 9
    dbt ★ 14K

    dbt enables data analysts and engineers to transform their data using the same practices that software engineers use to build applications.

    Apache-2.0 Rust pushed 2026-09-17 details →
  10. 10
    trino ★ 13K

    Official repository of Trino, the distributed SQL query engine for big data, formerly known as PrestoSQL (https://trino.io)

    Apache-2.0 Java pushed 2026-09-17 details →
method stars desc · snapshot from github api refresh nightly related Compliance & Risk Management, Human Resources (HR), Legal, E-commerce Platforms, Document Management & E-Signatures, Forms & Surveys

Related best-of lists

best Compliance & Risk Management →best Human Resources (HR) →best Legal →best E-commerce Platforms →best Document Management & E-Signatures →best Forms & Surveys →

last updated nightly · ranking method: github stars, live-tracked

Looking for a replacement for one specific commercial product? Browse alternatives by tool →

Frequently asked questions

What is the best open source Marketing & Customer Engagement tool in 2026?

duckdb leads the ranking with 41,440 GitHub stars, ahead of Krayin. Rankings use live GitHub star counts, refreshed nightly.

How is this list of Marketing & Customer Engagement tools ranked?

By GitHub stars — a proxy for adoption and community size. Each entry also shows its licence, primary language and last commit date, so you can judge maintenance activity rather than trusting the ranking alone.

Are the best Marketing & Customer Engagement tools free?

Every project on this list is open source and free to self-host. Some also offer paid managed hosting, but the software itself carries no licence fee.