While Bitrix24 isn't a traditional free open-source project, its Self-Hosted On-Premise edition offers the exact same benefits of code transparency and architectural freedom.
Access to features missing in lower cloud tiers, such as the Helpdesk module and the e-Commerce shop platform. bitrix24 open source
For those preferring containerization, community solutions like trydirect/bitrix24 offer Docker Compose deployment with PHP 7.0-Apache, supporting both Business and Enterprise editions. While Bitrix24 isn't a traditional free open-source project,
The open-source edition of Bitrix24 includes many of the same features as the proprietary version, such as: bitrix24 open source
Compare for the Self-Hosted vs. Cloud editions?
A completely free, enterprise-ready open-source CRM. It is highly customizable and serves as an excellent alternative to Bitrix24’s sales modules.