NLnet Foundation Open Calls: €5,000–€50,000 Grants for Free and Open Source Internet Projects, Reopening 3 September 2026 With a 3 November 2026 Deadline

NLnet Foundation Open Calls: €5,000–€50,000 Grants for Free and Open Source Internet Projects, Reopening 3 September 2026 With a 3 November 2026 Deadline

NLnet Foundation is one of the few funders in the world that will hand a working developer tens of thousands of euros to improve a piece of internet infrastructure, without demanding a university affiliation, a registered company, matched funding, or equity. It has been doing this since 1989, and over the past decade it has run rolling open calls roughly every two months under the Next Generation Internet banner.

That rhythm has paused. As of early August 2026, the submission form at nlnet.nl/propose carries a plain notice: it is not currently possible to submit proposals. NLnet says it is “taking stock of a decade of NGI Zero” and preparing the transition to a new effort called the Open Internet Stack. New calls for several funds will open on 3 September 2026, with a deadline of 3 November 2026 at 12:00 CEST (noon).

If you have been sitting on an idea for a protocol implementation, a hardening pass on a widely used library, a hardware design, or an accessibility overhaul of an open source tool, this gap is the useful part. You have roughly a month before submissions open and two months after that — enough time to write something considered rather than something rushed at the deadline.

Key Details at a Glance

What NLnet Actually Funds

The eligible-activity list published alongside the NGI Zero calls is unusually broad, and worth reading literally rather than skimming. Financial support is available for scientific research; design and development of free and open source software and open hardware; validation or constructive inquiry into existing or novel technical solutions; software engineering to adapt code to new usage areas or improve quality; formal security proofs, security audits, and the setup of testing and continuous integration; documentation for researchers, developers and end users, including educational material; standardisation activities, including membership fees for standards bodies; user requirements work and usability or inclusive design; packaging and other work that broadens deployability; participation in technical and community events such as IETF, W3C, RIPE meetings and FOSDEM, including admission, travel and subsistence; project management; and out-of-pocket infrastructure costs essential to the above.

That list quietly answers questions applicants often get wrong. Writing documentation is fundable. Attending a standards meeting is fundable. Paying for a CI runner is fundable. Project management time is fundable. What is not fundable is a project whose primary objective is something other than research and development — a pure advocacy campaign, a conference you want to host, or a service you intend to operate commercially without a technical development core.

Two thematic funds have run alongside the general calls and show the kind of specificity NLnet likes. NGI TALER funds work on privacy-preserving digital payments built on GNU Taler, with at least €676,000 reserved for open calls and a programme running to August 2027. NGI Fediversity funds work on a NixOS-based hosting stack that makes self-hosted, portable services such as Mastodon, PeerTube, Owncast and Lemmy practical to run, with €450,000 allocated and a programme running to November 2027. Both funds ran calls that closed on 1 August 2026. The broader NGI Zero Commons Fund — 21.6 million euro across a programme running from January 2024 to June 2027 — held its thirteenth and final call on 1 June 2026 and is no longer taking new applications.

NLnet has not yet published the full list of which funds will feature in the 3 September reopening, only that “several funds” will open. Treat the thematic pages as a guide to house taste rather than a guarantee of scope, and check the call-specific guide for applicants once the calls are live.

Grant Sizes and the Rule That Caps Your First Application

The stated target range is €5,000 to €50,000. The boundary conditions behind it are firm and stated in the guide for applicants:

• A first proposal may request up to €50,000. A proposal larger than that must be preceded by one or more smaller NGI0 projects that have been successfully concluded — meaning deliverables published under recognised open licences, software artefacts made WCAG compliant, and the findings of an independent security audit satisfactorily addressed.
• Any project above €50,000 may be subject to a full independent security audit at the end, performed by a party chosen by or agreed with NGI0. Payment of part of the grant can be made conditional on that audit and on how you handle what it finds.
• The maximum per proposal is €150,000. The maximum to any single third party — an individual or an organisation — over the lifetime of the NGI Zero Commons Fund is €500,000.

The design here is deliberate: NLnet would rather run many small bets in rapid succession than a few large ones. Teams that deliver can come back and ask for more, and are judged against the same criteria as everyone else in that round. If you are new to the funder, do not try to design a €120,000 project. Carve out the twelve-month slice that stands on its own, deliver it, and apply again.

Who Can Apply, and What “European Dimension” Means

There are no categorical exclusions of persons who may receive support. Individuals apply and win. So do informal teams, small companies, foundations, and university groups. You do not need a legal entity to submit.

Geography is a preference, not a gate. Given equal proposals, inhabitants of the EU and countries associated to Horizon Europe are given priority. Proposals from outside those areas can still be eligible where the project is of exceptional quality, the proposer holds unique technical expertise, and there is a clear European dimension. In practice, “European dimension” means being able to name the European users, communities, standards bodies, or infrastructure your work serves — not a sentence asserting relevance, but specific projects, deployments, or working groups.

Age is not a barrier either. Applicants who have not reached the age of legal consent in their country on the deadline date may apply without constraint; consent from a legal guardian is not needed to submit, only to enter negotiations later.

The Application Form, Field by Field

The form is short by grant standards, and NLnet says so itself — it calls the procedure lightweight and tells applicants not to waste time on attachments. Everything is plain text; if you need markup to make a point, attach it. Reviewers explicitly do not care about spelling or whether English is your first language.

You will be asked for contact details (name, email, phone, organisation, country), the call you are responding to, a proposal name, and a project website or wiki. Then the substantive fields:

• Abstract. Explain the whole project and its expected outcomes, and describe any prior involvement you have had with relevant projects or organisations, including what you personally contributed.
• Requested amount, in euro.
• Budget explanation. What the money will be used for, whether the project has other funding sources past or present, a breakdown of main tasks with associated effort, and explicit rates. A full budget can be attached.
• Comparison. How your project compares with existing or historical efforts.
• Technical challenges. The significant ones you expect to solve, if any.
• Ecosystem. Who the relevant actors are, how you will engage them, and how you will promote the outcomes.
• Generative AI disclosure. You must state whether you used generative AI in writing the proposal. If you did, you are asked for the model, what you used it for, the dates of the prompts, the prompts themselves, and the unedited output — either pasted in or attached.

Attachments may be HTML, PDF, OpenDocument or plain text, up to 50 MB in total, and are meant to be background only. The proposal must be self-contained and concise without them.

Two operational notes from NLnet worth heeding: draft long answers offline in case your browser session fails, and do not submit in the final hour. Deadlines are hard.

How Proposals Are Scored

Assessment runs in two stages, and the weights are published.

Stage one begins with knock-out eligibility checks: the proposal must be in English, in line with the NGI vision and the specific call, have research and development as its primary objective, and meet any hard criteria for that call, such as a clear European dimension. Anything that fails is marked ineligible and goes no further. Surviving proposals are scored on three criteria — technical excellence and feasibility at 30%, relevance, impact and strategic potential at 40%, and cost effectiveness and value for money at 30%. A weighted score above 5.0 out of 7 is needed to advance.

Stage two selects for lasting impact. Reviewers can ask clarifying questions and suggest improvements, and they independently verify facts, methods and claims through their expert network. The published examples of those questions tell you exactly what to pre-empt: how your approach differs from named existing projects; how you will handle a specific complicating factor; whether you can back up or validate a claim; whether you have considered collaborating with a complementary effort or adopting a relevant standard; why a particular task rate is high relative to its apparent value; how the outcome becomes self-sustaining; and how the upstream project feels about your application.

Budgets can change in this phase as milestones are added or removed. If you cannot answer within the allotted window, your project may be moved to the next call rather than rejected. Revised plans are re-scored, and if the revision scores lower than the original, the original stands. Projects are then ranked and a cut-off is set based on the quality of the round and remaining budget.

A standing independent review committee of unpaid experts from the internet and open source world, academia and the public sector then checks the final selection, with at least two members reviewing each project for eligibility and frugality. If a project fails at that stage, the concerns go back to the proposer and the project is pushed to the next call.

Building a Budget Reviewers Will Accept

Cost effectiveness carries 30% of the score, and the second-stage questions show reviewers challenge rates line by line. Three things help:

Make the rates explicit and defensible. State a day rate or hourly rate and the number of days per task. Vague lump sums invite the “this rate is very high compared to the perceived value of that task” question.

Break the work into milestones that are independently verifiable. NLnet pays against delivered work under a memorandum of understanding, so a plan built from concrete, checkable deliverables is both easier to score and easier to get paid for.

Be honest about other funding. The form asks about other sources past and present. Disclosing a small existing grant is not a problem; discovering one later is.

The final amount is set by NGI Zero based on projected cost and estimated value, adjusted for ineligible costs and for any extra activities they recommend, and fixed in the MoU. If you do not like the number offered, you can withdraw the proposal at any point before signing. Because NLnet is a recognised Dutch public benefit organisation and these grants fall within its statutory mission, awards are treated as charitable gifts under favourable tax conditions — a detail worth raising with your accountant rather than assuming applies to your situation.

The Support Services That Come With a Grant

Grantees get access to a set of services the NGI Zero coalition provides free, delivered by specialist partners: accessibility auditing including WCAG audits (HAN University of Applied Sciences), business consulting and mentorship through the Business Circle (APELL), community building and mentoring (CCT), copyright and licence due diligence (FSFE), diversity and inclusion (APC), internationalisation and translation, technical writing, testing strategies, troubleshooting and UX design (CCBV), open source quality and compliance (OW2), packaging (NixOS), security audits (ROS), and standardisation (TN).

Two practical points: these come in limited supply and are allocated first come, first served, and most are cheaper to act on early. A security audit or accessibility review requested at the start of a project shapes the work; requested at the end, it generates a backlog. Grantees from the wider NGI ecosystem, including those who have already concluded an NGI0 project, can request services through the NGI Zero Review programme.

Timeline and What Happens Next

• Now until 3 September 2026 — submissions closed. Use the time to draft offline, tighten scope, and talk to the upstream projects you plan to touch.
• 3 September 2026 — calls open across several funds. Read the call-specific guide for applicants and eligibility page for whichever fund fits; scope and hard criteria differ between them.
• 3 November 2026, 12:00 CEST — deadline. Hard.
• Within a few days of the deadline — NLnet contacts applicants.
• After that — first-stage scoring, then second-stage questions for shortlisted projects, then independent review committee sign-off, then a memorandum of understanding.

NLnet also runs an open office hour on the last Wednesday of each month at 16:00 CET in its Matrix room, with a session scheduled for 26 August 2026. That is the cheapest way to sanity-check whether an idea fits before you invest days in writing it up.

Common Mistakes

Writing about why the problem matters instead of what you will build. The form says it directly: focus on the what and the how, not the why. Reviewers already believe the internet needs fixing.

Skipping the comparison question. “Compare your own project with existing or historical efforts” is where weak proposals collapse. If you cannot name the alternatives and say precisely where you differ, reviewers will find them and draw their own conclusions.

Ignoring upstream. Reviewers ask how the upstream project feels about your application. If you are proposing work on someone else’s codebase, tell them first and say in the proposal that you have.

Padding the attachments. NLnet asks applicants not to waste time on them. A self-contained proposal with one clear budget attachment beats a thirty-page dossier.

Treating the AI disclosure as optional. It is a form field with a published policy behind it. If you used a model, say so and supply the prompts.

Submitting at 11:55. The site warns twice that deadlines are hard and that browser sessions fail. Submit a day early; you can update before the deadline, and the last complete version is what gets reviewed.

Frequently Asked Questions

Can I apply as an individual with no company? Yes. There are no categorical exclusions, and individuals are funded regularly.

Can I apply from outside Europe? Yes, but the bar is higher. Equal proposals favour applicants in the EU and Horizon Europe associated countries, and applicants elsewhere need exceptional quality, unique expertise, and a clear European dimension.

Do I have to open-source everything? Yes. Releasing software, hardware and content under free/open licences, applying open standards where possible, and publishing scientific results open access are transversal requirements across all NLnet funds.

How much should I ask for? For a first application, somewhere between €5,000 and €50,000, matched to a scope you can genuinely deliver. The €150,000 ceiling is reachable only after you have concluded smaller NGI0 work successfully.

What if my idea does not fit any fund cleanly? NLnet explicitly invites out-of-the-box submissions and notes that an idea that does not fit one fund may suit another. The office hour is the place to ask.

Which funds will be in the September round? NLnet has said “several funds” without naming them all as of early August 2026. That list is not confirmed; check the propose page on 3 September.

Official Links

• Application form and current call status: https://nlnet.nl/propose/
• All funding programmes: https://nlnet.nl/funding.html
• NGI Zero Commons Fund guide for applicants: https://nlnet.nl/commonsfund/guideforapplicants/
• Eligibility information: https://nlnet.nl/commonsfund/eligibility/
• Support services for grantees: https://nlnet.nl/NGI0/services/

If you build or maintain anything in the open source internet stack, put 3 September 2026 in your calendar and start drafting now. The form is short, the money is real, and the review process is more transparent than almost anything else at this size.