Top trending OSS startups in Q2 2025
Runa Open Source Startup (ROSS) index is a regular ranking of early-stage open-source startups, based on their GitHub star growth rate in the last quarter.
We have been publishing the top trending open-source startups every quarter since Q2 2020. More than 30,000 developers, founders, and investors have visited the ROSS index to date. Here's our fresh top 10 for Q2 2024 — we hope you enjoy it! 😊
🇺🇸 Union Labs (unionlabs/union, 54.2K stars, 54.2x growth) is a modular zero-knowledge interoperability layer linking blockchains. Founded in 2023 in Dover, DE. Raised $16M from Semantic, Tioga, Galileo, Nascent, LongHash, gCC, etc.
🇺🇸 Linera (linera-io/linera-protocol, 21.2K stars, 14.6x growth) develops a blockchain protocol for highly scalable, low-latency Web3 apps. Founded in 2021 in San Francisco. Raised $12M from Andreessen Horowitz, Borderless, Tribe, etc.
🇺🇸 Sesame (sesameailabs/csm, 13.4K stars, 13.4x growth) designs voice-first AI eyewear and a companion assistant. Founded in 2022 in San Francisco. Raised $57.6M from Andreessen Horowitz, BIG, Matrix, Spark, etc.
🇸🇬 Mindverse (mindverse/second-me, 12.8K stars, 12.8x growth) develops SecondMe, a locally run AI doppelganger that keeps all your data private. Founded in 2022 in Singapore. Raised $29.9M from Square Peg, Hongshan, K2VC, Linear, Plug and Play Tech Center, HSG.
🇨🇭 Browser Use (browser-use/web-ui, 11.5K stars, 11.5x growth) is a toolkit that lets AI agents control a browser, automating end-to-end web workflows. Founded in 2024 in Zurich. Raised $17.5M from Y Combinator, Felicis, SV Angel, Pioneer, Nexus, Liquid 2, A.Capital etc.
🇺🇸 Prefect (jlowin/fastmcp, 10.6K stars, 10.2x growth) built Python workflow orchestration. Now developing FastMCP 2.0, a Pythonic toolkit to build MCP servers for tool-enabled LLMs. Founded in 2018 in Washington, DC. Raised $60M from Positive Sum, Atreides, Operator, Bessemer, Quiet, Tiger.
🇺🇸 Mastra (mastra-ai/mastra, 11.8K stars, 9.9x growth) provides a TypeScript agent framework with cloud workflows and observability. Founded in 2024 in San Francisco. Raised $0.5M from Y Combinator, Pioneer, SAV, Orange Collective, etc.
🇸🇬 DUIX (duixcom/duix.heygem, 9.7K stars, 9.7x growth) provides a digital-human SDK for real-time interactions. Founded in 2017 in Singapore.
🇫🇷 Lightpanda (lightpanda-io/browser, 8.2K stars, 8.2x growth) is a Zig-built headless browser optimized for AI automation. Founded in 2022 in Paris. Raised an undisclosed amount from ISAI, Kima, Factorial, etc.
🇺🇸 Oumi (oumi-ai/oumi, 8.1K stars, 8.1x growth) builds open-source frontier AI models through a global community. Founded in 2024 in Seattle, WA. Raised $10M from Plug and Play, Ascend, Obvious, Venrock, etc.
Get more data about other startups from the last quarter at ROSS Index Q2 2025.
Our portfolio company Keep was acquired by Elastic
Last year, we led a $2.5M pre-seed round (thesis) in an open-source AIOps & alert management startup 🇮🇱 Keep, and in May 2025, it was acquired by another great open-source company, Elastic (NYSE: ESTC).
Congratulations to all Keep's founders: Tal and Shahar, who continue building its very impressive product at Elastic, and Matvey, who has embarked on building his third startup right after the acquisition!
How does the ROSS index work?
The index evolves with the support of its community, and in Q1 2024, we slightly tweaked our methodology. Now the startup list is based on maximum GitHub star growth within any 90-day period that ended in the target quarter. In a nutshell, our approach remains simple:
Monitor all GitHub repos with 1,000+ stars
Calculate the growth of stars during the target "sliding window" period
Select repos that are only associated with early-stage startups
Highlight the top 20 trending open-source startups by their GitHub star growth
There's no magic open metric representing the quality of tech companies. Our star growth-based approach highlights noteworthy early-stage startups leveraging open source that have been on developers' minds in the last quarter.
Since its launch in Q2 2020, all quarterly indexes are published on our website. You can easily contact us with your ideas on how to improve the index. Also, if you’re a lucky participant in the ROSS index’s top 20, feel free to let others know about this by adding a special badge on your GitHub repo or to your website.
We ❤️ Open Source
Besides the ROSS index, we maintain our own open source repo: awesome list of open-source alternatives to established SaaS products. It already has 17,000+ stars and 100+ contributors. Join them or just give it a star 😊