The Linux Foundation | 03 June 2025
Div2525, TXO, SmarterStack and Interoperable Building Box invite industry-wide collaboration through open source
SAVANNAH, Ga., – Realcomm IBCon – June 3, 2025 – The Linux Foundation, the nonprofit organization enabling mass innovation through open source, today announced the induction of four technical projects contributed by the Coalition for Smarter Buildings Foundation (C4SB Foundation). Furthering its efforts to modernize building management through open collaboration, the C4SB Foundation contributed Div2525, Technology Exchange Optimization (TXO), SmarterStack, and Interoperable Building Box (IBB).
The C4SB Foundation brings together domain experts, technology innovators and building owners to accelerate the adoption of smart building technologies. These technical projects address long-standing fragmentation in building management systems by establishing open frameworks that support interoperability, simplify procurement, and drive performance innovation. The projects now have a neutral, community-driven home, thus increasing visibility, collaboration, and long-term sustainability.
“We’re excited to bring Div2525, TXO, SmarterStack and IBB into the Linux Foundation,” said Jim Zemlin, Executive Director of the Linux Foundation. “With these contributions, the community has increased access to the tools needed to refresh an industry that is ripe for change.”
“The building management industry has struggled with vendor lock-in, poor interoperability, and a lack of shared standards for decades,” said Rick Justis, Executive Director of the C4SB Foundation. “By bringing these projects together under a neutral home as the Linux Foundation, we’re taking concrete steps toward shaping the future of smart buildings – together."
Contributed technical projects include:
- Div2525: A standardized taxonomy for describing building technology systems, Div2525 provides a common language for specifying and procuring building infrastructure. By making product capabilities more transparent and comparable, it reduces confusion in RFPs and helps buyers avoid vendor lock-in.
- Technology Exchange Optimization: TXO introduces a structured framework for evaluating and aligning operational technology capabilities across buildings and portfolios. It supports better decision-making by helping teams benchmark existing assets, identify interoperability gaps, and guide technology upgrades.
- SmarterStack: This open reference architecture helps vendors and customers visualize how commercial products map to open interfaces and integration points. SmarterStack improves transparency, speeds up deployment of modular systems, and accelerates conformance with smart building standards.
- Interoperable Building Box: IBB delivers plug-and-play interoperability tools – including device abstraction layers, sample code, and implementation guides – that simplify integration across hardware and software ecosystems. It lowers engineering overhead, enhances device flexibility, and lays groundwork for scalable AI and automation use cases.
The projects will benefit from the governance, technical support, and ecosystem engagement that the Linux Foundation provides to its hosted projects.
Industry leaders supporting these efforts include, Engenuity, Padi.io, We Write Code, SkyCentrics, Cimetrics and Ace IOT. In addition, the C4SB Foundation is collaborating with the community via the Ontology Tiger Team – which includes leaders and stakeholders from key partners such as ASHRAE, NIST, Project Haystack, LBNL, BRICK, LonMark, and RealEstateCore – to further their shared vision of using interoperable semantic ontology, and improve interoperability and user experience for building owners and managers.
Real estate professionals, building owners, facilities managers, and technology providers can learn more and get involved at our website. Technical contributors can join project working groups at github.com/c4sbf.
Supporting Quotes:
"Interoperability has been a guiding principle for LonMark and a personal mission of mine for decades. The C4SB Foundation's decision to bring their open source and open specification initiatives under the Linux Foundation is a powerful step forward for the industry. This alignment underscores our shared commitment to unlocking seamless integration across building systems and signals that the time for real, scalable interoperability has finally arrived."
– Tracy Markie, Chairman, LonMark International
"This is a historic moment—watching the Linux Foundation, a titan in open source, begin to actively support the buildings industry is like watching a long-awaited bridge being built between two worlds. The C4SB Foundation’s projects bring the kind of collaborative innovation our sector has needed for decades. It’s a much-needed breath of fresh air that I believe will drive a new era of openness and agility in smart buildings."
– Ken Sinclair, Publisher, Automated Buildings
"Innovation moves faster when it’s built on open, community-developed standards rather than trapped in proprietary silos. The C4SB Foundation’s move to partner with the Linux Foundation accelerates this shift in the built environment. We’ve seen time and again how open ecosystems lead to better outcomes—and this is exactly the kind of momentum that will unlock transformative value for building owners, solution providers, and the broader market."
– Glen Allmendinger, Founder, Harbor Research
Media Contact
Kristi Piechnik
Linux Foundation
kpiechnik@linuxfoundation.org