The fastest-growing open-source startups in Q4 2021

Snapshot of ROSS Index featuring top open-source startups by Github stars growth of their repositories. All descriptions below are based on public data and were up-to-date at the end of Q4 2021.
  1. CodeNotary (codenotary/immudb, 6.4K stars, 1636% AGR). Software supply chain audit based on the immutable database. Founded in 2018 in Houston and raised $7M from Elaia, Bluwat, Acequia Capital.
  2. Datree (datreeio/datree, 5.2K stars, 1391% AGR). Automated policy checks for Kubernetes pipelines. Founded in 2017 in Tel Aviv and raised $11M from Blumberg Capital, TLV Partners, Y Combinator.
  3. Appsmith (appsmithorg/appsmith, 11K stars, 1088% AGR). Framework for the building of admin panels, CRUD apps and workflows. Founded in 2019 in Bengaluru and raised $8M from Canaan Partners, Bessemer, Accel, OSS Capital.
  4. Rowy (rowyio/rowy, 2.5K stars, 882% AGR).  Extendable Airtable-like spreadsheet UI for databases. Founded in 2021 in Sydney and has no known external funding. 
  5. Modulz (radix-ui/primitives, 2.7K stars, 774% AGR). Code-based tool for designing and prototyping. Founded in 2019 in Dublin and raised $5.4M from LocalGlobe, Frontline, Tiny VC.
  6. Fonoster (fonoster/fonoster, 3.8K stars, 638% AGR). Unified communication and telephony API (open-source alternative to Twilio). Founded in 2015 in Cameron, NC (USA) and has no known external funding. 
  7. Budibase (budibase/budibase, 8.2K stars, 609% AGR). Low-code platform for the building of internal tools. Founded in 2020 in Belfast and raised $391K from Techstart Ventures.
  8. Bytebase (bytebase/bytebase, 1.8K stars, 597% AGR). Database schema change and version control for teams. Founded in 2021 in Shanghai and raised $3M from Matrix Partners China. 
  9. QuestDB (questdb/questdb, 7.7K stars, 549% AGR). Time-series database. Founded in 2019 in London and raised $14.3M from Episode 1, Y Combinator, 468 Capital, etc.
  10. Builder (builderio/mitosis, 3.8K stars, 548% AGR). Low-code platform for building frontend (headless CMS). Founded in 2018 in San Francisco and raised $17.3M from Greylock, etc.
  11. Rainbow (rainbow-me/rainbow, 2K stars, 417% AGR). Mobile Ethereum wallet for managing assets. Founded in 2019 and raised an unknown round from Digital Currency Group.
  12. Netless (netless-io/flat, 3.2K stars, 397% AGR). Professional interactive whiteboard SDK. Founded in. 2018 in Hangzhou and raised $1M. 
  13. Fig (withfig/autocomplete, 8.5K stars, 335% AGR). Autocomplete for the terminal. Founded in 2020 in San Francisco and raised $2.4M from General Catalyst, SV Angel and YC.
  14. deepset (deepset-ai/haystack, 3.5K stars, 306% AGR). NLP-based semantic search engine for enterprises. Founded in 2018 in Berlin and raised $1.6M from Tiny VC, Lunar Ventures, System.One, Acequia Capital, etc. 
  15. OpenReplay (openreplay/openreplay, 3K stars, 301% AGR). Session replay software (open-source alternative to Fullstory). Founded in 2018 in Paris and raised $1.5M from Kima Ventures and YC.
  16. Mattermost (mattermost/focalboard, 7.1K stars, 295% AGR). Collaboration platform (open-source alternative to Slack). Founded in 2015 in Palo Alto and raised $70M from S28, Y Combinator, Redpoint, Battery Ventures, etc.
  17. Nomic Labs (nomiclabs/hardhat, 2.2K stars, 279% AGR). A platform for development on Ethereum. Founded in 2018 in Buenos Aires and has no known external funding.
  18. Logseq (logseq/logseq, 8.6K stars, 266% AGR). Knowledge base manager. Founded in 2020 in Hangzhou and has no known external funding. 
  19. Jitsu (jitsucom/jitsu, 2K stars, 257% AGR). Data ingestion engine (open-source alternative to Segment). Founded in 2019 in San Francisco and raised $2M from Costanoa Ventures, SignalFire, Y Combinator, etc.
  20. Evidently (evidentlyai/evidently, 2K stars, 242% AGR). Toolset to analyze and monitor machine learning models in production. Founded in 2020 in London and raised $125K from Y Combinator. 

Visit ROSS Index to see the recent top-20 open-source startups.