# Open Source Endowment (OSE)

> The world's first endowment fund dedicated to sustainably funding critical free and open source software.

## Overview

The Open Source Endowment Foundation is a US 501(c)(3) tax-exempt public charity (EIN 33-3502715) founded on February 14, 2025. It collects donations from the open source community, invests all of them into diversified assets, and spends only the investment returns to support critical yet underfunded open source software globally.

- Website: https://endowment.dev
- GitHub: https://github.com/osendowment
- Donate: https://endowment.dev/#donate

## How It Works

1. **Fundraise**: Individuals, companies, and foundations donate to form a permanent principal.
2. **Invest**: The principal is invested in a diversified portfolio managed by Infinite Giving (outsourced CIO), targeting 7-8% annual returns.
3. **Grant**: 5% of the fund is spent annually on grants to critical open source projects, selected via a data-driven model.
4. **Monitor**: Grantee projects are tracked for accountability and iterative improvement.

## Key Facts

- Model: Endowment (spend only investment returns, preserve principal forever)
- Legal: US 501(c)(3) tax-exempt nonprofit (Delaware)
- Address: 2261 Market Street Suite 91962, San Francisco, CA
- Investment Manager: Infinite Giving (specializing in US nonprofits)
- Target Return: 7-8% annually
- Target Spend Rate: 5% of fund per year on grants
- Grant Format: Microgrants (up to $5,000) to eligible high-risk candidates among most valuable OSS

## Team

### Board of Directors
- Konstantin Vinogradov (Chairman) — VC investor, former GP at Runa Capital ($600M+ AUM), creator of ROSS Index
- Amy Parker (Secretary) — VP, Major Gifts at the Signal Foundation, former Deputy Executive Director at OpenSSL Foundation and Director of Wikipedia Endowment
- Maxim Konovalov (Treasurer) — Co-founder and former CTO of Nginx (400M+ websites), former VP Engineering at F5
- Chad Whitacre (Director) — Former Head of Open Source at Sentry, former leader of Open Source Pledge, founded Gratipay

### Staff & Advisors
- Jonathan Starr (Executive Director) — Former Program Manager at NumFOCUS
- Vlad-Stefan Harbuz (Advisor) — Director of Open Source Pledge, core developer at thanks.dev

## Grant Selection Model

OSE uses a data-driven scoring approach based on:
- **Value**: downloads, dependencies, dependents, criticality — implemented as OpenSSF Criticality Score (60%), ecosyste.ms critical-infrastructure flag (20%), PageRank position within the strongest ecosystem (10%), cross-ecosystem dependency mass (10%)
- **Risk**: geometric mean of concentration (bus factor + HHI), complexity (LOC + cyclomatic), security (OpenSSF Scorecard + CVEs), and maintainer workload
- **Eligibility**: open source AND active AND nonprofit AND funding intent (a plain AND of four booleans)
- Final score is sqrt(value x risk), so both dimensions must be high

The model is published openly at https://github.com/osendowment/model

## Governance

- **Donors**: All individual and institutional contributors
- **Members**: Donors of $1,000+/year gain advisory rights and participate in governance
- **Board**: 4 directors (expandable to 11); must also be Members

## Get Involved

- **Nominate an OSS project** for a grant: https://endowment.dev/funding — open to anyone, self-nominations welcome.
- **Nominate a board director candidate**: https://endowment.dev/nominate-board — open to anyone, self-nominations welcome. To be elected, Directors must be OSE Members (donors giving $1,000+/year). Reviewed on a rolling basis against OSE's needs — fundraising, investment management, open source expertise. Directors are elected for a three-year term.
- **Become a Member**: donate $1,000+/year.

## Contact

- General: konstantin@endowment.dev
- Donors: donations@endowment.dev

## Further Reading

- About: https://endowment.dev/about
- Nominate OSS: https://endowment.dev/funding
- Nominate a board director: https://endowment.dev/nominate-board
- FAQ: https://endowment.dev/faq
- Docs: https://endowment.dev/docs
- Community: https://endowment.dev/community
- Full details for LLMs: https://endowment.dev/llms-full.t