Top trending open-source startups in Q4 2025

Snapshot of ROSS Index featuring top open-source startups by GitHub stars growth of their repositories. All descriptions are based on public data and were current as of the end of Q4 2025
  1. 🇺🇸 Firecrawl (firecrawl/open-lovable, 21.6K stars, 21.6x growth) develops web data API for AI. Recently released Open Lovable app that recreates any website. Founded in 2020 in San Francisco. Raised $17.6M from Agent, Nexus, Zapier and Y Combinator.
  2. 🇺🇸 Coze (coze-dev/coze-studio, 18.1K stars, 18.1x growth) develops Coze Studio, an AI agent development platform with visual tools. Founded in 2023 in Mountain View, CA. Raised $75M.
  3. 🇺🇸 Strix (usestrix/strix, 17.1K stars, 17.1x growth) runs autonomous AI agents for penetration testing. Founded in 2024 in San Francisco. Raised an undisclosed amount from Vercel.
  4. 🇺🇸 Charm (charmbracelet/crush, 14.3K stars, 14.3x growth) develops Crush, a terminal-based AI coding agent. Founded in 2019 in New York. Raised $9.9M from Fuel, NAP, Firestreak, Betaworks, Gradient, etc.
  5. 🇸🇬 Sapient (sapientinc/HRM, 11.4K stars, 11.4x growth) develops brain-inspired hierarchical reasoning model. Founded in 2024 in Singapore. Raised $22M from Jafco, Sumitomo and Vertex.
  6. 🇺🇸 Memori Labs (MemoriLabs/Memori, 11.1K stars, 11.1x growth) develops memory layer for AI agents. Founded in 2024 in New York. Raised $3.7M from F7, Oceans, RiverPark and Struck.
  7. 🇺🇸 Bytebot (bytebot-ai/bytebot, 9.5K stars, 9.5x growth) is an AI desktop agent that automates computer tasks through natural language. Founded in 2024 in San Francisco.
  8. 🇺🇸 Stellon Labs (KittenML/KittenTTS, 9.0K stars, 9.0x growth) builds tiny AI models, including Kitten TTS — a high-quality voice synthesis model under 25MB. Founded in 2025 in Sacramento, CA. Raised $0.5M from 468, Alpen, Berkeley Frontier, Transpose Platform Management and Y Combinator .
  9. 🇺🇸 Dyad (dyad-sh/dyad, 15.0K stars, 8.9x growth) is an AI app builder that lets you craft full-stack interfaces from your machine. Founded in 2025 in San Jose, CA.
  10. 🇨🇳 RustFS (rustfs/rustfs, 8.7K stars, 8.7x growth) is a high-performance s3-compatible distributed object storage system built in Rust. Founded in 2023 in Beijing.
  11. 🇺🇸 BosonAI (boson-ai/higgs-audio, 7.5K stars, 7.5x growth) focuses on expressive speech and audio AI. Recently released Higgs Audio V2, a state-of-art audio foundation model. Founded in 2023 in Santa Clara, CA.
  12. 🇺🇸 humanlayer (humanlayer/humanlayer, 6.6K stars, 6.5x growth) is an open-source IDE for AI coding agents orchestration. Founded in 2023 in San Francisco, CA. Raised $0.5M from Hawk Hill, Multimodal, Pioneer, Preface and Y Combinator.
  13. 🇺🇸 Pickle (pickle-com/glass, 6.4K stars, 6.4x growth) builds a set of tools to create living digital clones. Founded in 2024 in San Francisco. Raised $6M from Pioneer, Rebel, HorizenNet, Y Combinator, NFX, Krew, Unpopular, Bass, Kulveer Taggar, Nate Matherson.
  14. OpenCut (OpenCut-app/OpenCut, 40.2K stars, 6.2x growth) is a cross-platform video editor. Founded in 2025.
  15. 🇺🇸 Kilo Code (Kilo-Org/kilocode, 10.6K stars, 5.8x growth) is an AI coding assistant. Founded in 2025 in Wilmington, DE. Raised $8M from Breakers, Cota, General Catalyst, Quiet and Tokyo Black.
  16. 🇬🇧 Bloop (BloopAI/vibe-kanban, 5.5K stars, 5.5x growth) builds Vibe Kanban, an orchestration tool that runs and tracks multiple AI coding agents simultaneously. Founded in 2021 in London. Raised $7.43M from FinTech Innovation Lab, Ascension, ByTheTower, Khosla, etc.
  17. 🇬🇧 Automaze (automazeio/ccpm, 5.5K stars, 5.5x growth) builds tools for CTO-as-a-Service, including CCPM — a project management system for Claude Code. Founded in 2023 in London.
  18. 🇺🇸 Jaaz (11cafe/jaaz, 4.9K stars, 4.9x growth) is a content creation multimodal agent. Founded in 2023 in the United States.
  19. 🇦🇺 Superdesign (superdesigndev/superdesign, 4.7K stars, 4.7x growth) is an AI product design agent. Founded in 2025 in Sydney.
  20. 🇮🇱 Emcie (emcie-co/parlant, 16.1K stars, 4.7x growth) develops Parlant, a customer-facing AI agent with predictable, guideline-driven behavior and reliable rule compliance. Founded in 2023 in Tel Aviv. Raised an undisclosed amount from NFX.
  21. Anyone with a featuring on ROSS Index Q4 2025 can add the badge to their own website to let site visitors know they are one of the fastest-growing open-source startups.

    Visit ROSS Index to see the top-20 open-source startups in other quarters.