Self Hostable Open Source Alternatives to Commercial products

Analytics

(Alternatives to MixPanel,Google Analytics, Amplitude)

• Matomo (https://github.com/matomo-org/matomo)
• Posthog (https://github.com/PostHog/posthog)
• Countly (https://github.com/Countly/countly-server)

Appointment Scheduling

(Alternative to Calendly)

• Cal (https://github.com/calendso/calendso)

Backend As A Service

(Alternative to Firebase)

• Appwrite (https://github.com/appwrite/appwrite)

Data Pipelines

(Alternative to Fivetran)

• Melanto (https://meltano.com/)
• Airbyte (https://airbyte.com/)

APM

(Alternative to DataDog)

• Signoz (https://signoz.io/)

Low Code Internal Tools

(Alternative to Retool)

• Appsmith (https://github.com/appsmithorg/appsmith)
• ToolJet (https://github.com/ToolJet/ToolJet)
• Budibase(https://github.com/Budibase/budibase)

Newsletter and Mailing List Manager

• ListMonk (https://github.com/knadh/listmonk)

No Code Database

(Alternative to Airtable)

• NoCodb (https://github.com/nocodb/nocodb)
• Baserow (https://github.com/bram2w/baserow)

Note Taking Apps

(Alternative to Notion, Evernote)

• Athens (https://github.com/athensresearch/athens)

Password Management Solutions

• bitwarden (https://github.com/bitwarden)

Session Replay Tools

Session replays show you how individual users explore your website—right down to their mouse movements and the places they click.
(Alternative to LogRocket,FullStory,SmartLook)

• rrweb (https://github.com/rrweb-io/rrweb)
• open replay (https://github.com/openreplay/openreplay)

Video Conferencing

(Alternative to Google Meet, Skype)

• Jitsi (https://github.com/jitsi/jitsi-meet)

Will try to keep the list of self hostable open source projects updated