The Open Cloud Mesh initiative started in 2015 within the GÉANT Association. Here follows a brief history of the project, including pointers to all known technical presentations held over the years, with their recordings where available.
Origins of the project at GÉANT
- In December 2013, the GÉANT Association (formerly known as TERENA) and ownCloud Inc. made an agreement that served to facilitate the desire of various National Research and Education Networking organisations (NRENs) to introduce services based on ownCloud technology and/or to offer the technology to their constituencies. Such technology appeared to be the most promising in order to provide on-premise file-based sync&share.
- As part of this collaboration effort, in January 2015, ownCloud initiated an idea to interconnect the individual on-premise private cloud domains at the server side in order to provide federated sharing functionalities between different administrative domains, with an initial implementation draft dating July 2015 as subsequently reported.
- The initiative was presented at the 17th TF-Storage Meeting, October 2015 (slides available from the web archive) and at the Cloud Sync&Share Storage (CS3) Workshop 2016 to an emerging community of vendors, NRENs and other institutions, led by CERN. A follow-up presentation took place at CS3 2017.
- Following that initial effort, implementations appeared in the market featuring a
1.0-proposal1OCM API version, prior to official standardization. A Campfire-style discussion about current developments and standardization plans was held at CS3 2020. - Minutes of the early meetings and actions are available at the GÉANT wiki.
The EU-funded CS3MESH4EOSC project
- In January 2020, a consortium of NRENs and independent actors of the CS3 community, led by CERN, kick-started the CS3MESH4EOSC project.
- Technical Workshop held in June 2020: the
1.0.0version of the OCM API was officially published. On the occasion, the OCM repository was migrated to the cs3org GitHub Organization. The standard was already implemented by ownCloud, Nextcloud and Seafile, and used in production to federate multiple instances. - Paper presented at CHEP 2021 about the emerging ScienceMesh federation.
- Automated tests initiated and hosted by PonderSource.
- OCM Workshop held at CS3 2021.
- OCM Interoperability Session held at the CS3 2022.
- Several OCM-related talks are given at CS3 2023.
- In May 2023, an extended version 1.1 of the API was published, which included much of the development effort driven by the CS3MESH4EOSC project.
- In June 2023, members of the CS3MESH4EOSC project presented at the EGI 2023 conference, demonstrating the ScienceMesh and its OCM-based federation capabilities with live demos.
NL-net funded efforts
- In June 2023 a grant was awarded in order to continue the developments and specifically improve the specifications and the testing.
- In October 2023 a W3C Community Group was launched.
- A Campfire and Panel session about OCM took place at CS3 2024, held back at CERN on its 10th anniversary. Subsequently, the CS3 community initiated thematic SIGs, including an OCM SIG.
- The OCM Test Suite was revamped, and the specification underwent a major rewrite in order to improve clarity and adopt the IETF Internet-Draft format.
- Technical Workshop held in November 2024: version 1.2 was published and the Internet-Draft document was presented.
- Presentation at FOSDEM 25.
- In March 2025, the team was invited to present the Internet-Draft document at the IETF Meeting 122. The presentation was postponed to the next meeting, as it clashed with the CS3 2025 event.
- At CS3 2025 the OCM CS3 SIG held a session to report on its activity.
- The Internet-Draft document was presented at IETF 123, as part of the Dispatch session (recording). Version 1.2.1 was published in preparation for that event. Following a successful dispatch, a non-WG IETF mailing list was provided to initiate the standardization process.
- The wiki is launched to collect minutes of the ongoing meetings.
- The W3C Community Group, with 24 participants, was archived in August 2025 as work transitioned to the IETF mailing list.
- In preparation for the IETF WG, a charter was submitted to define its mandate.
- Presentation about the standardization efforts at NORDUnet Community Workshop 2025.
- The IESG amended and approved the WG charter, and voted the formation of the Working Group, which became official on October 23rd, 2025. Version 1.2.2 was published on the occasion, with all refinements accepted so far before the WG starts its mandate.
- To gather interest on the just-formed WG, a HotRFC talk (recording) was given at IETF 124.
Sovereign Tech Fund commissioned efforts
- In October 2025 funding was awarded to implement several missing pieces and introduce automated testing in each vendor's CI pipeline, as well as to support the IETF standardization efforts. This engagement was first made public at the Open Source at CERN in 2025/2026 event, featuring a number of funding agencies including Sovereign Tech, with a lightning talk about CERNBox and OCM.
- Presentations and demonstrations about the OCM-based EOSC Federation of Cloud Storage Systems at the EOSC Symposium 2025.
- First IETF WG interim meeting held in November 2025 (recording): the draft is officially adopted by the WG.
- The 16th SIG-CISS Meet-up on Federated Storage and Storage Infrastructure (recording part 1 and part 2) featured a number of presentations about storage federations and OCM, including an OCM 10th anniversary presentation.
- In March 2026 three simultaneous events featured the project:
- A HotRFC presentation (recording) followed by informal gatherings at IETF 125 with the IETF experts.
- Panel at the CS3 2026 event, where the CS3 SIG reported on the activity and on the latest version 1.3, recently published, as well as on the WG plans.
- The International Symposium on Grids & Clouds (ISGC) 2026 hosted a presentation about OCM and the IETF standardization effort.