PESO is a five-year software-ecosystem stewardship and advancement project, advancing the DOE Office of Advanced Scientific Computing Research (ASCR) scientific software ecosystem by coordinating stewardship, integration, and quality-focused activities across a diverse portfolio of DOE-funded software projects.
How PESO is organized and funded
PESO’s annual budget is $4M, supporting about 40 staff members at 8 DOE labs, four industry partners, and one university. By design, many PESO team members also receive funding from partner software stewardship organizations (SSOs), enabling close coordination and reducing duplication of effort across the CASS portfolio. Roughly 75 percent of PESO’s budget funds cross-SSO collaboration:
- Technical collaborations (~54%) — strengthening interoperability, testing, and infrastructure among SSOs, organized into PESO’s six thrusts.
- Spack and E4S (~25%) — direct support for the two cornerstone PESO products that deliver and curate the DOE Office of Science’s software portfolio.
- Community and outreach collaborations (~21%) — promoting visibility and broad adoption of DOE scientific libraries and tools, and workforce development.
How we work with CASS
Through collaborations within the Consortium for the Advancement of Scientific Software (CASS), PESO provides shared infrastructure, coordination, and stewardship practices that improve interoperability, quality, and adoption across a diverse software portfolio spanning applied math (FASTMath), AI/data/visualization (RAPIDS), programming models and runtimes (S4PST), and tools for performance and correctness (STEP). These activities are designed to complement — not replace — product-level stewardship by individual teams and SSOs.
PESO leads or significantly staffs several CASS working groups, including Software Ecosystem, Integration, Impact Framework, Software Quality Assurance, and User-Developer Experience — the same five thrusts detailed on the Thrusts page. A CASS-wide Impact Framework, developed and led by PESO, gives the consortium a common, transparent way to track software stewardship activities and progress across the whole portfolio.
Looking forward: AI and the Genesis Mission
PESO is positioning the scientific software ecosystem to support AI-for-Science workflows, including emerging world-model approaches that combine data-driven methods with equation-based simulation components. Rather than treating AI as a standalone activity, PESO integrates AI considerations into ecosystem stewardship — emphasizing reproducibility, software quality, usability, and interoperability as AI becomes a central element of scientific discovery. This work aligns directly with DOE’s Genesis Mission, which calls for rapid increases in scientific productivity through the convergence of simulation, data, and AI. See how PESO can help Genesis Mission teams.
Community and outreach
PESO supports leadership for the CASS Steering Committee and multiple working groups, and staffs a range of cross-SSO initiatives that cultivate the scientific software workforce and public visibility — including the Better Scientific Software (BSSw) program and the High Performance Software Foundation (HPSF). See the CASS page for PESO’s specific leadership roles across the consortium.
Want to be part of this? See how to connect with PESO or meet the team.