laudspeaker

Laudspeaker is an Open Source Customer Engagement and Product Onboarding Platform. Open Source alternative to Braze / One Signal / Customer Io / Appcues / Pendo. Use Laudspeaker to design product onboarding flows and send product and event triggered emails, sms, push and more. Maintained by laudspeaker on GitHub, where it has earned 2,609 stars from the community.

It's actively developed around checklist-guides, customer-engagement, customer-journey, and is a solid reference for anyone building with these tools.