Pebble's Open Source Revival: A Guide to Its Enduring Legacy

The story of Pebble is one of innovation, community, and ultimately, resilience. Once a trailblazer in the smartwatch market, Pebble captured hearts with its e-paper displays, long battery life, and a vibrant developer ecosystem. Despite its initial success, the company faced challenges, leading to its acquisition by Fitbit in 2016, which itself was later acquired by Google. For many, this marked the end of an era for their beloved smartwatches. However, thanks to a dedicated community and a significant move by Google and Pebble’s founder, the Pebble smartwatch software stack is now entirely open source, breathing new life into the platform.

A modern smartwatch displaying code on its screen, symbolizing open source software — Photo by Shawn Rain on Unsplash

A Journey Through Ownership and Openness

Pebble’s commitment to openness began early, with the company making its SDK and various libraries available as open source projects. This fostered an enthusiastic developer community that crafted thousands of watchfaces and applications, enriching the user experience far beyond what a closed ecosystem might allow.

When Fitbit acquired Pebble in 2016, official support for Pebble devices eventually ceased, leaving many users concerned about the longevity of their smartwatches. In response, a grassroots movement known as the Rebble project emerged. This community-driven initiative painstakingly reverse-engineered and rebuilt critical cloud services, including the app store, firmware updates, and voice dictation, effectively keeping Pebble watches functional. The Rebble project became a testament to the power of open source and community dedication in preserving technology.

A pivotal moment arrived in January 2025 when Google, having inherited Pebble’s intellectual property through its acquisition of Fitbit, announced the open-sourcing of the core Pebble operating system, PebbleOS. This monumental step, driven by a team at Google that included former Pebble employees, provided the foundational software for developers to build upon. Pebble founder Eric Migicovsky, who had been working on a new iteration of Pebble-like smartwatches under his company Core Devices, spearheaded the final push. In November 2025, Core Devices declared that the entire Pebble software stack was now “100% open source,” including the previously elusive mobile companion apps for Android and iOS. This complete liberation of the software stack ensures that the platform can truly thrive independently, driven by the community that has cherished it for so long.

Diving Deep: What’s Now Open Source?

The full open-sourcing of Pebble’s software encompasses several key components, providing developers with unprecedented access and control:

PebbleOS (Firmware)

The heart of the Pebble smartwatch, PebbleOS, is built upon the FreeRTOS real-time operating system. This firmware provides all the standard smartwatch functionalities, from notifications and media controls to fitness tracking and support for custom applications. Developers can now access, modify, and compile the entire operating system. While some proprietary binary blobs remain necessary for certain hardware components like heart rate sensors or the Bluetooth stack (which are common limitations in hardware development), the core Pebble watch software stack is entirely open and can be compiled and run without these non-free elements. The firmware supports applications written in C and JavaScript (via the Jerryscript engine), maintaining compatibility with the vast library of existing Pebble apps.

Mobile Companion Applications

One of the most critical additions to the open-source ecosystem is the mobile companion app for Android and iOS. Historically, the absence of an open-source mobile app was a significant hurdle for community efforts. Core Devices resolved this by publishing the source code for their new Pebble mobile app on GitHub, built using Kotlin Multiplatform. This allows a single codebase to generate native applications for both platforms, ensuring that users can connect their watches and access essential features long into the future. The libpebble3 library, also open source, further facilitates cross-platform development by providing the core logic for interacting with Pebble devices, separating it from UI concerns.

Developer Empowerment and the Tools of Creation

The full open-sourcing extends beyond just the core software, encompassing the very tools developers use to create for Pebble. This includes the Pebble SDK (Software Development Kit), which provides libraries, documentation, and the necessary compilers to build watchfaces and applications. Now, the community has full control over the SDK’s evolution, allowing for enhancements, bug fixes, and even the addition of new features that might not have been considered by the original developers. The open-source nature means that developers can now improve the toolchain itself, potentially optimizing compilation times, adding support for new C language features, or even integrating with modern development environments.

For those eager to dive in, the open-source release also includes the Pebble emulator, a crucial component for testing applications without needing physical hardware. This emulator, now fully transparent, can be enhanced to provide better debugging capabilities, more accurate hardware simulations, or even support for hypothetical new Pebble devices envisioned by the community. This level of access transforms the platform from a consumer product with a developer API into a truly hackable device where every layer of the software stack is accessible and modifiable. The implications are profound: developers are no longer constrained by the vision or resources of a single company, but by the collective ingenuity of a global community.

The Evolution of the Rebble Project

With Google’s and Core Devices’ momentous decision, the role of the Rebble project, while still vital, shifts significantly. Having spent years meticulously rebuilding critical services, Rebble’s efforts laid the groundwork for the current open-source landscape. The project demonstrated the feasibility and power of a community-driven approach. Now, instead of reverse-engineering and maintaining shadow services, Rebble can transition to becoming the primary custodian and orchestrator of the open-source Pebble ecosystem.

This means Rebble can focus on integrating the newly liberated software components, migrating its existing user base to the official open-source services, and establishing governance models for future development. The community can collectively decide on feature priorities, security updates, and even the direction of new hardware support. For instance, the Rebble app store, once a re-creation, can now integrate directly with the official open-source app repository, ensuring a seamless experience for users and developers alike. Voice dictation services, previously managed by Rebble, can now leverage the open-source stack for more robust and transparent implementations, potentially even allowing for self-hosting options for privacy-conscious users. The Rebble community’s dedication has not just preserved Pebble; it has paved the way for its enduring renaissance.

Future Horizons: Beyond the Original Vision

The complete open-sourcing of Pebble’s software stack unlocks a myriad of future possibilities, far exceeding the initial scope of the original company. For existing Pebble users, it guarantees the longevity of their devices, ensuring that their smartwatches will remain functional and even gain new capabilities for years to come. Updates to the mobile companion apps, for example, can ensure compatibility with future versions of Android and iOS, preventing obsolescence due to operating system changes.

Beyond maintenance, developers can now explore entirely new avenues. Imagine custom PebbleOS builds optimized for specific use cases, such as ultra-low-power operations, enhanced security, or integration with emerging smart home standards. New watchfaces and applications can leverage modern web technologies or even connect to decentralized services, transforming the Pebble into a truly open edge device. The libpebble3 library, being cross-platform, could even facilitate the development of Pebble integration into unconventional devices or operating systems, creating bridges where none existed before.

There’s also the tantalizing prospect of new hardware. While Core Devices is already exploring new Pebble-like devices, the open-source software stack lowers the barrier for other hardware enthusiasts or manufacturers to create compatible smartwatches. A truly open hardware and software ecosystem could emerge, fostering innovation in wearable technology driven by community needs rather than corporate roadmaps. The Pebble, once a symbol of innovation, has been reborn as a testament to the power of open collaboration and the enduring spirit of its community. It’s a platform now truly owned by its users and developers, poised for a future as dynamic and diverse as the community that champions it.

Conclusion

The journey of Pebble, from a Kickstarter sensation to an open-source marvel, is a compelling narrative of innovation, challenge, and ultimately, the triumph of community. What began as a pioneering smartwatch company evolved into a symbol of resilience, thanks to the unwavering dedication of its user and developer base. The strategic decision by Google and the leadership of Pebble founder Eric Migicovsky, culminating in the complete open-sourcing of the entire Pebble software stack in November 2025, marks a pivotal moment. This move not only safeguards the legacy of existing Pebble devices but also ignites a new era of collaborative development. With PebbleOS, mobile companion apps, and the entire toolchain now freely available, developers are empowered to innovate without constraints, ensuring that the beloved e-paper smartwatches will continue to evolve, adapt, and surprise for years to come. The story of Pebble is far from over; it has merely entered its most exciting, and truly open, chapter.

References

Google LLC (2025). PebbleOS Open-Source Initiative Announced. Available at: https://blog.google/pebbleos-open-source-2025/ Migicovsky, E. (2025). Core Devices Liberates Full Pebble Software Stack. Available at: https://coredevices.com/blog/pebble-100-percent-open-source Rebble Alliance (2025). The Rebble Project: Community Sustaining Pebble Smartwatches. Available at: https://rebble.io/ Kotlin Multiplatform (2025). Official Documentation. Available at: https://kotlinlang.org/lp/multiplatform/ FreeRTOS (2025). The FreeRTOS Kernel. Available at: https://www.freertos.org/