Zenodo is a free, general-purpose open repository built and operated by CERN and OpenAIRE, launched on May 8, 2013 with backing from the European Commission's open-data policy. Its name honors Zenodotus, the first librarian of the Ancient Library of Alexandria. Unlike a journal or a subject preprint server, Zenodo is a catch-all archive: it accepts research outputs from every discipline and in every format - datasets, software, preprints, published papers, posters, presentations, images, videos, lesson materials, and supplementary files.

Every upload receives a persistent DataCite DOI, making even "small" outputs like a figure or a cleaned dataset formally citable. Data is stored in the CERN Data Centre in Geneva, backed up nightly with geographic redundancy in Budapest, and retained for the lifetime of the repository - tied to CERN's own multi-decade operational horizon. Zenodo also hosts the EU Open Research Repository for outputs from Horizon Europe, Euratom, and earlier Framework Programmes, and runs on the open-source InvenioRDM framework.

1. Create a free account. Sign up with email, GitHub, or ORCID - linking ORCID keeps your outputs attached to your researcher profile.
2. Upload your files. Up to 50 GB and 100 files per record by default; a one-time increase to 200 GB can be requested for a single record. Bundle many small files into a ZIP.
3. Describe the record. Add title, authors, description, keywords, funding, and a resource type. Good metadata is what makes your record findable; all Zenodo metadata is released under CC0.
4. Choose a license and access level. For public files you pick the license (CC BY and CC0 are common defaults for data; any license is allowed, including software licenses like MIT or GPL).
5. Publish. The record and its DOI go live immediately - there is no waiting time and no editorial queue. Note that files cannot be silently swapped after publishing; changes happen through versioning.

Zenodo does not perform peer review or editorial screening. Its acceptance policy is deliberately permissive - any research status, any field - with reactive moderation: content that violates privacy, copyright, or confidentiality can be reported and removed. Treat a Zenodo record the way you would treat a preprint or an unreviewed dataset: the DOI guarantees persistence and citability, not scientific validation.

Every record carries a DataCite DOI, and Zenodo displays ready-made citations in common styles on the record page. Two DOI types matter:

• Version DOI - points to one specific version of the record. Use it when reproducibility depends on the exact files (e.g., the exact software release used in your analysis).
• Concept DOI - a top-level DOI that always resolves to the latest version and represents all versions together. Use it when citing the work in general.

A typical dataset citation looks like: Author(s). (Year). Title (Version) [Data set]. Zenodo. https://doi.org/10.5281/zenodo.XXXXXXX - then adapt to your target journal's citation style.

Zenodo's GitHub integration archives a snapshot of your repository every time you cut a GitHub release and mints a new version DOI for it, under one concept DOI for the project. Adding a CITATION.cff file to the repository controls the author list and citation metadata. This is the de facto standard way to make research code citable.

Depositing on Zenodo is not journal publication, and for most journals it does not count as prior publication - the same norm that covers preprint servers. Common patterns: archive the dataset and code that underpin a manuscript and cite their DOIs in the paper (many journals and funders now require exactly this); post a preprint or accepted manuscript where the journal's self-archiving policy allows; or deposit supplementary materials too large for the journal's own system. Always check your target journal's preprint and data policies before posting, and check your funder's rules - EU-funded projects in particular are steered toward Zenodo via OpenAIRE.

Zenodo is completely free: no deposit fees, no access fees, no APCs. It is funded by CERN, OpenAIRE, and the European Commission, with additional support through the CERN & Society Foundation. The realistic "cost" is your time preparing good metadata - which is also what determines whether anyone finds and reuses your work.