Kai A. Hartung

Kai A. Hartung

ToolJet

ToolJet

The open-source low-code framework for React developers. A SOC 2 Type II compliant alternative to Retool with air-gapped deployment capabilities.

Strapi

Strapi

The leading open-source Headless CMS. A customizable, developer-first content API that replaces Contentful and Sanity.

Outline

Outline

The beautifully designed, source-available team knowledge base. A self-hosted alternative to Notion and Confluence for teams who value documentation speed.

Metabase

Metabase

The easiest way for teams to ask questions of their data. An open-source BI tool that democratizes analytics for non-technical users.

InvoiceNinja

InvoiceNinja

The leading open-source invoicing and billing platform for freelancers and agencies. A powerful, self-hostable alternative to FreshBooks and QuickBooks.

ClickHouse

ClickHouse

The fastest open-source OLAP database on earth. A real-time analytics powerhouse that replaces Snowflake and BigQuery for petabyte-scale data.

Budibase

Budibase

The open-source low-code platform for building secure internal tools. A highly compliant, ISO 27001-certified alternative to Retool and Microsoft PowerApps.

BillionMail

BillionMail

The self-hosted email marketing platform with a built-in MTA. A high-risk, high-reward alternative to Mailchimp that offers unlimited sending but requires strict governance oversight.

Typebot

Typebot

A visual, no-code chatbot builder that lets you create advanced conversational apps and embed them anywhere (Web, WhatsApp) with high conversion rates.

Listmonk

Listmonk

A high-performance, self-hosted newsletter and mailing list manager that provides enterprise-grade mass-mailing capabilities without the recurring per-subscriber tax.

DocuSeal

DocuSeal

A secure, open-source alternative to DocuSign that enables businesses to automate document workflows and legally binding signatures with full data sovereignty.

Odoo

Odoo

The giant of Open Source ERPs. Powerful but complex, with a significant feature gap between the Free Community edition and the Paid Enterprise version.

NocoDB

NocoDB

The 'Bring Your Own Database' Airtable alternative. Turn any MySQL, Postgres, SQL Server, or SQLite database into a smart spreadsheet.

ERPNext

ERPNext

The 100% Open Source alternative to Odoo. A monolithic ERP with Accounting, HR, and Manufacturing included out of the box.