Illinois · Nonprofit
THE HDF GROUP
THE HDF GROUP (Illinois) receives grants from 3 organizations whose IRS filings report $181,700 to it, the largest being University of Notre Dame du Lac ($169,570). 2 of them have funded it in more than one year, and 93% of the money arrives through donor-advised or pass-through sponsors rather than from an institution directly.
- Revenue FY2025
- $3.0M
- Funders on record
- 3
- Grants received
- $182k
- Net assets
- $1.6M
What The Hdf Group does
Mission
The organization's primary exempt purpose is to ensure the sustainability of hdf technologies and ongoing accessibility of hdf-stored data for the government agencies and organizations that have mission-critical systems relying on hdf. Specifically, the organization's mission is to develop and maintain free, open source computer applications that move and store scientific and complex data among disparate computing systems. There are over 200 different types of computer applications using hdf technologies, and an estimated 1.6 million users of national aeronautics and space administration (nasa) data alone, in hdf formats.
As stated on its FY2025 Form 990.
Program
The Hdf Group researched, developed, and tested modifications to hdf5 to expand functionality, improve performance, and increase usability of hdf5.
$2,345,605 spent$2,819,158 earned by the program100% of program spending
The program described on its FY2025 Form 990. Program spending in total: $2,345,605.
The organization over time
Each line starts at 100 in 2017, so what you read is the shape rather than the size: 150 means half as much again as 2017, 50 means half. The number beside each label in the key is where it ended. The shaded band is where the middle 50% of its peers' revenue would sit, given their growth.
Balance sheet
Total assets and total liabilities at each year end, in dollars. The largest one-year move in total assets was 2023 to 2024, from $3.2M to $2.4M (−27%).
How it's funded, over time
Each bar is one year's revenue split into where it came from, and every bar is the same height — these are shares, not amounts, so a year that raised twice as much looks the same size. Hover a bar for the split.
Government-grant reliance: 2023 19%. Grants only. Government contracts and fees sit inside program revenue.
0% of THE HDF GROUP’s revenue is contributions — more earned-revenue than three-quarters of its peers (67% for the typical peer).
Surplus & reserves
Operating surplus or deficit each year, and months of liquidity in hand. 5 of the last 9 reported years ran a deficit.
reserve
Leadership and staff
The officers, directors, trustees and key employees listed on each return. Joined and no longer listed compare each filing with the year before, matching people by surname and first initial; a year after a gap, or a roster under three people, has no comparison.
Chief executive
Gerd Heber
Executive director
As listed on its FY2025 Form 990.
Who funds it, year by year
2017 → 2023: the base broadened from 1 funder to 2 funders, grant income rose $12k → $18k.
2 of 3 of your funders are donor-advised or pass-through sponsors (tagged DAF) — 93% of grant dollars received. That money is really individual donors directing a sponsor; the institutions to cultivate are the non-DAF funders.
From the IRS filings of THE HDF GROUP’s funders (the co-funder graph). Association, not causation. Trends are read to FY2023, the last fiscal year that has finished arriving. FY2024–FY2026 are still being filed and are shown unshaded; they do not move any figure on this page.
How concentrated its funding is
THE HDF GROUP leans on a few funders — its largest provides 93% of grant income and the top three 100%; half comes from just 1 funder.
the vertical line marks half of all grant income — 1 funder to its left
93% of the income these shares are computed over arrives through pass-through sponsors or from payers whose filings do not say what kind of payment it is. Concentration is still measured over all of it, because the money is real; what it does not support is a claim about how many institutions have chosen to fund THE HDF GROUP.
Largest funder’s share by year: 2017 100% · 2020 100% · 2021 100% · 2022 100% · 2023 100% — broadly stable.
“Effective funders” = inverse Herfindahl index (1 / Σ shareᵢ²) — the number of equal-sized funders that would give the same concentration. Trends are read to FY2023, the last fiscal year that has finished arriving. FY2024–FY2026 are still being filed and are shown unshaded; they do not move any figure on this page.
Where its funders are
93% of THE HDF GROUP's grant income arrives through donor-advised or pass-through sponsors, whose addresses record where the money is held rather than where the donor is. Of the $12k that is directly attributable, 100% of it comes from funders outside Illinois, across 1 state.
Funder states come from each funder’s own filing. $170k arriving through sponsors registered in 2 states is excluded from the map and the split above: a sponsor holds money on a donor’s behalf, so its registered address would place those dollars somewhere no donor need ever have been. Trends are read to FY2023, the last fiscal year that has finished arriving. FY2024–FY2026 are still being filed and are shown unshaded; they do not move any figure on this page.
Against its field
THE HDF GROUP is better cushioned than half of the 210 science & tech nonprofits its size.
this organization peer median middle 50% of peers· 210 science & tech nonprofits $1M–$10M, FY2025
Government funding THE HDF GROUP receives
Grants and contracts to this organization from federal (USASpending) and state checkbooks, reconciled to its EIN. $4.5M on record.
- Department of Energy$2.0M
- National Science Foundation$1.5M
- National Aeronautics and Space Administration$1.1M
Federal grants vs contracts are distinguished; state line items keep their reported category. Matched by name + geography (the BMF), so coverage is partial and precision-first.
Organizations like THE HDF GROUP
Organizations whose mission and program text most resemble this one, by semantic similarity over every organization in the US filings — the closest peers, and often the clearest route to shared or prospective funders.
In Illinois
Nationally
Read directly from this organization’s own Form 990, as neutral context.
Where the money goes
74% of spending goes to programs.
Governance
Public support
99%
Share of support from the public (Schedule A) — the basis for its public-charity status.
Footprint & structure
Files a return copy in 2 states
Screen this organization
A dated, signed PDF of the compliance screen for THE HDF GROUP: IRS status (Business Master File, Publication 78, auto-revocation), the OFAC sanctions lists, the Internal Revenue Bulletin, and California registration, with the Rev. Proc. 2018-32 §8.01 reliance elements stated element by element. Generated from the current files at the moment you download it.
Screens are triage, not determinations; a source that cannot be read reports not screened, never clear. Screen this nonprofit · How the screen works · on the API as GET /api/screening/{ein}?format=pdf
Questions and answers
- Who funds THE HDF GROUP?
- THE HDF GROUP (Illinois) receives grants from 3 organizations whose IRS filings report $181,700 to it, the largest being University of Notre Dame du Lac ($169,570). 2 of them have funded it in more than one year, and 93% of the money arrives through donor-advised or pass-through sponsors rather than from an institution directly.
- How many funders does THE HDF GROUP have?
- IRS filings report 3 organizations giving $181,700 in grants to THE HDF GROUP, 2 of which have funded it in more than one year.
- Who is the largest funder of THE HDF GROUP?
- University of Notre Dame du Lac is the largest funder on record, with $169,570 in grants. The full list of funders is on this page.
- How can an organization like THE HDF GROUP find more funders?
- Start with the funders already giving here, then look at the foundations that back similar organizations in Illinois. The funding by cause and by state pages list the largest funders for a given area and how to approach them.
These figures are read directly from IRS Form 990 / 990-PF e-file XML: this organization’s own return for FY2025 (financials across 2017–2025), and the filings of 3 funders that report grants to it. “On record” means captured in the filings we have parsed — a funder that does not e-file, or whose grant detail is not itemized, will not appear. Filings run roughly 12–24 months behind. Trends on this page end at FY2023, the last fiscal year that has finished arriving; later years are shown and marked, and move no figure. Data on this page was exported October 14, 2026. What this page cannot tell you · view filing