The NSF POSE program — formally the Pathways to Enable Open-Source Ecosystems solicitation — funded the creation of managing organizations that turn a promising open-source research product into a self-sustaining, community-governed open-source ecosystem (OSE). POSE did not fund software development itself; it funded the organizational, governance, and community-building work needed to keep an already-viable open-source tool alive and growing after the original research grant that built it runs out.
As of the FY2026 funding cycle, NSF has replaced POSE with a successor solicitation, NSF 26-506, Pathways to Enable Secure Open-Source Ecosystems (PESOSE). Research administrators searching for "NSF POSE" today are, in practice, looking for PESOSE — this page covers both: what POSE (NSF 24-606, now archived) funded, and how PESOSE extends and restructures it.
What POSE funded, and why NSF created it
NSF-funded research routinely produces open-source software, models, and platforms that prove genuinely useful beyond the lab that built them — but most research grants are not structured to fund the ongoing maintenance, governance, documentation, and community management a tool needs once it has real external users. A tool can be scientifically important and technically solid and still collapse the moment the graduate student who maintained it graduates. POSE was NSF’s response to that gap: rather than funding more code, it funded the managing organization around existing code — the governance structure, contributor onboarding, sustainability planning, and community infrastructure that lets a research tool keep being developed by a distributed community instead of a single lab.
NSF’s own definition of an open-source ecosystem, carried forward into PESOSE, centers on three components: a distributed intellectual-content developer community (contributors from multiple organizations, not just the originating lab), third-party end users who depend on the product, and a managing organization that ensures the whole thing keeps functioning — handling things like licensing, releases, code review standards, and financial sustainability.
POSE’s original phase structure (NSF 24-606, archived)
The original POSE solicitation used a two-phase structure:
- Phase I — Scoping and planning. Up to $300,000 for up to one year. Phase I funded the diagnostic work: determining whether a product was actually ready to become an OSE, whether a real early-adopter user base existed, and whether a distributed contributor community was plausible. A Phase I award was not a prerequisite for Phase II — teams that could already demonstrate scoping readiness could apply directly to Phase II.
- Phase II — Establishment and expansion. Up to $1,500,000 for up to two years, for products that already had external users and outside contributors, to build out the managing organization and governance model at scale.
Eligible open-source products, under POSE, had to already be publicly accessible (preferably under an open-source license) and already have some external third-party users or outside contributors — POSE explicitly did not fund building a tool from scratch or growing a first user base.
PESOSE (NSF 26-506): the current program and its three tracks
PESOSE keeps POSE’s core Phase I / Phase II structure but adds a third track focused on security, and folds security considerations into the program’s framing throughout — NSF describes PESOSE as supporting ecosystems that are not just sustainable but explicitly safe and secure, positioning the investment as relevant to U.S. innovation, economic competitiveness, and national security, not just open science. NSF announced an investment of up to $40 million through the initiative, with roughly 60 awards anticipated across the three tracks.
| Track | Focus | Award ceiling | Duration | Approx. awards |
|---|---|---|---|---|
| Track 1 | Scope and plan an OSE (equivalent to legacy Phase I) | $300,000 | Up to 1 year | ~30 |
| Track 2 | Establish and expand a sustainable OSE (equivalent to legacy Phase II) | $1,500,000 | Up to 2 years | ~10 |
| Track 3 | Improve the safety, security, and privacy of an existing OSE | $1,500,000 | Up to 2 years | ~10 |
Track 3 is the substantive addition: it is open to ecosystems that already exist (including ones that did not necessarily come through POSE or PESOSE Track 1/2) and funds hardening their security, privacy, and safety posture rather than their initial formation. PESOSE’s definition of an open-source product is also broader than POSE’s software-centric framing — NSF describes eligible OSE components as including software, hardware, machine learning models, languages, and data platforms that are publicly accessible and modifiable.
Who is eligible
Eligible proposing organizations under PESOSE include:
- U.S.-accredited institutions of higher education (two- and four-year)
- Non-profit, non-academic organizations
- For-profit organizations, provided they are U.S.-based and U.S.-owned and controlled (majority equity held by U.S. citizens, permanent residents, or eligible U.S. entities)
- State and local governments
- Federally recognized Tribal Nations
- Other federal agencies and FFRDCs
For PI eligibility at an institution of higher education, the individual must hold a tenured or tenure-track position, a primary full-time paid research or teaching appointment, or a staff leadership role in an Open-Source Program Office (OSPO), and be based at a U.S. campus by the submission deadline. At non-academic organizations, the PI must be an employee of the proposing organization normally resident in the U.S.
Deadlines and how to apply
PESOSE does not require a letter of intent. Full proposals are due on the first Tuesday in September and the first Tuesday in March each year (5 p.m. local time of the submitting organization), submitted through NSF’s standard proposal channels (Research.gov or Grants.gov) under solicitation NSF 26-506. Because POSE (NSF 24-606) is now archived, proposals should be prepared against the current PESOSE solicitation text rather than the older POSE solicitation, even where program mechanics carried over unchanged.
Which NSF directorates fund it
PESOSE is a cross-directorate solicitation, not owned by a single NSF unit. Participating directorates include the Directorate for Technology, Innovation and Partnerships (TIP) — which has led much of the program’s public framing — alongside the Directorate for Computer and Information Science and Engineering (CISE), Biological Sciences, Engineering, Geosciences, Mathematical and Physical Sciences, Social, Behavioral and Economic Sciences, and STEM Education. This breadth reflects that open-source research products worth sustaining come out of essentially every science and engineering field NSF funds, not just computing.
How POSE/PESOSE differs from a standard NSF research grant
Research administrators evaluating whether POSE/PESOSE is the right mechanism for a PI’s tool, versus a standard research grant or a program like an NSF center-scale mechanism, should note the key distinction: POSE/PESOSE explicitly does not fund new feature development or first-time community building from zero. It funds the organizational and governance layer around a product that already has external validation — real outside users, real outside contributors, or both. A PI whose tool has no users yet is not a fit for Track 1 or Track 2; a PI with an established, adopted tool who needs to build a sustainability plan, formalize governance, or (under Track 3) harden the project’s security posture is the intended applicant.
Frequently asked questions
Is NSF POSE still an active program?
The original POSE solicitation, NSF 24-606, is archived. Its function has been carried forward and expanded under NSF 26-506, Pathways to Enable Secure Open-Source Ecosystems (PESOSE), which is the current active solicitation as of the FY2026 cycle.
What is the difference between POSE and PESOSE?
PESOSE preserves POSE’s original two-phase structure (relabeled Track 1 and Track 2, with identical award ceilings and durations) and adds a new Track 3 specifically for improving the safety, security, and privacy of an existing open-source ecosystem. PESOSE’s eligible-product definition is also broader, explicitly naming hardware, machine learning models, and data platforms alongside software.
Does a team need a Phase I / Track 1 award before applying for Phase II / Track 2?
No. NSF has stated that a Phase I (POSE) or Track 1 (PESOSE) award is not a prerequisite for a Phase II / Track 2 proposal, provided the team can otherwise demonstrate their product and community meet Track 2’s readiness bar.
Can a for-profit company apply to PESOSE?
Yes, provided the company is U.S.-based and U.S.-owned and controlled, with majority equity held by U.S. citizens, permanent residents, or eligible U.S. entities.
What counts as an open-source ecosystem under PESOSE?
NSF defines an OSE as a self-sustaining structure built around a publicly accessible, modifiable open-source product (software, hardware, ML models, languages, or data platforms) that has a distributed community of outside contributors, third-party end users, and a managing organization responsible for its ongoing sustainability.
