RunaCapital/ROSS-Index

ROSS Index

• 2020: Q2, Q3, Q4
• 2021: Q1, Q2, Q3, Q4
• 2022: Q1, Q2, Q3, Q4
• 2023: Q1, Q2, Q3, Q4
• 2024: Q1, Q2, Q3, Q4
• 2025: Q1, Q2, Q3, Q4
• 2026: Q1, Q2

Overview

Since Q2 2020, the ROSS Index publishes the top open-source startups by the relative growth rate of GitHub stars at their repositories. The calculation of the growth rate starts from the moment when a repo crosses a 1000-star mark, and the results are published every quarter.

The purpose of this index is to highlight new, trending open-source startups using a simple and transparent basis. It was created by Konstantin Vinogradov and is maintained by venture capital firm Runa Capital, which has invested early in many OSS startups, including n8n, Nginx, MariaDB, Twenty and Mastra.

Methodology

Why do we only use GitHub star growth?

We chose only one basic metric as, otherwise, it would be hard to verify the index results externally. Any composite and complex derivative metrics overcomplicate the picture and are better consumed internally.

We chose “stars” because it allows for a reasonable comparison between various repos using the same scale while showing trending open-source products. There is no perfect business metric for open-source software — all have their flaws. For instance, “contributors” are good for comparing “apples to apples” (e.g. databases), but can barely be used for different categories of software. Stars seem the best single metric for index purposes.

We measure the relative growth of stars (and not absolute) because it shifts focus from established open-source champions to interesting newcomers in the developer community. GitHub has network effects, so it is easier to acquire stars for already well-starred repos. But this index is about startups!

Calculation approach (since Q1 2026)

We rank repositories based on their maximum star growth rate over a 90-day window ending within the target quarter. The ranking criteria are:

1. The repo must have 1,000+ stars by the end of the target quarter.
2. If the repo had 1,000+ stars before the quarter, growth is calculated as (stars at period end) / (stars at period start) over any 90 consecutive days ending within the quarter.
3. If the repo crossed 1,000 stars during the quarter (or was created mid-quarter), we normalize growth to a 90-day baseline as (stars at quarter end) / 1,000, so it remains comparable with established projects.
4. The observation period always ends within the target quarter.

Repositories are then ranked by their growth rate in descending order. Our team only selects the repos belonging to startups and publishes the top-20 in the ranking. If a startup has several top repos, we will only mention the one with the best growth rate.

Startup definition

For purposes of the index, we define a “startup” as a product-focused commercial organization that

1. was founded fewer than ten years ago
2. raised less than $100M in total known funding
3. has a product reasonably connected to its open-source repos
4. was not acquired or went public before the end of the target period

This definition does not cover, for instance, side projects. For example, when a founder has another full-time job. Nor does it include projects without any associated commercial product-focused entity or those developed by large tech corporations. The definition also excludes businesses that are mostly focused on the provision of professional services.

Open source definition

As VC investors, here we stick to the commercial perception of an “open source company” - a tech business leveraging OSS playbook as an approach for product development and go-to-market strategy. So, we would consider, for example, MongoDB as an example of such a company, although their Server Side Public License is not approved by the OSI. The same applies to some source-available participants in the ROSS Index.

Data sources

The index publications are based only on public data from GitHub, Crunchbase, mass media, and other sources. We strive to show cities and countries connected with the origin of companies, not just formal HQ locations. We are purely focused on companies using English descriptions, so some local startups (e.g. Chinese) could be missed.

Given the open-source nature of data, some inaccuracies are possible. In any case, Runa Capital does not use any private information received from startups for the index. For instance, we may know that a company raised a new VC round but we will only publish publicly available numbers like those on Crunchbase.

Old calculation approach (2020-2025)

In 2020-2023, we calculated the relative growth of stars within a fixed period (quarter or year) for all repos with at least 1,000 stars at the start of the period. For those rankings, we used the annualized growth rate calculated as AGR = (value now / value 1 quarter ago)⁴ – 1.

From Q1 2024, we updated the approach with sliding “90-day windows” to detect fast-growing repos even if their growth spike happened between calendar periods. We still required repos to have 1,000+ stars at the start of the observation window to be eligible.

Since Q1 2026, repos qualify if they reach 1,000 stars by the end of the quarter, since AI-era projects often hit 1,000 stars in days rather than years. For repos younger than 90 days, we normalize growth to a 90-day baseline (stars at quarter end ÷ 1,000).

License

The datasets and all other contents of this repository are licensed under the Creative Commons Attribution–NoDerivatives 4.0 International License (CC BY-ND 4.0).

See the LICENSE.md file for details.