Santosh Mahto September 11, 2026 tl,dr: How Collabora partnered with the You Tube Cobalt and Device Partner Engineering teams to deliver the first RDK-based reference platform for their next-generation living room web engine. Switch on your Smart TV, open You Tube, and navigate to Settings → App Version, you might spot a version text like 25.lts. That’s the version of classic Cobalt, the lightweight, open source HTML5/CSS/Java Script engine meant specifically for resource-constrained embedded devices, which currently runs You Tube on living room devices such as Smart TVs, STBs, etc. Over the years, Cobalt has undergone a massive architectural transformation: the transition from classic Cobalt to Chrobalt, (Cobalt re-architected on top of Chromium).

At Collabora, as we continue our journey to accelerate, collaborate, and adopt open source, we have been working closely with Google's You Tube Cobalt and Partner Engineering teams to deliver the first-ever RDK-based Chrobalt reference platform for third-party devices, proving this major architectural evolution for device partners and OEMs worldwide. The Shift: From Cobalt to Chrobalt Historically, running a full-fledged browser engine like Chromium on low-power set-top boxes (STBs) and Smart TVs was out of the question due to tight RAM and CPU constraints. Google built Cobalt from the ground up to solve this exact problem, offering a minimal web standards subset optimized for media streaming and lean resource consumption.

Cobalt interfaced with hardware platforms through an abstraction layer called Starboard, allowing OEMs and So C vendors to port You Tube to custom silicon. However, maintaining an independent layout and rendering engine alongside the rapidly evolving modern web ecosystem is a massive undertaking. To bridge this gap, Google initiated a bold engineering effort: Merge Cobalt’s code with Chromium to get a robust, standard-compliant rendering pipeline.

The result is Chrobalt (starting with 26.eap and recently updated to 27.lts, tracking modern Chromium milestones like 138+). Now Chrobalt is a Chromium embedder with a Starboard porting layer. Thus Chrobalt combines the best of both worlds: Modern web features and rapid web security updates from upstream Chromium.

Starboard integration and low-footprint media pipelines tailored for TV and STBs hardware. There are reference ports for Desktop and Android, but the story is incomplete without providing some reference port for external device manufacturers to convince them about Chrobalt - So here we are. Collabora’s Role: Building the RDK Reference Platform For over a year, we engaged directly with Google’s You Tube Cobalt team and partner engineering team to port, integrate, and stabilize Chrobalt on an RDK (Reference Design Kit) platform for Amlogic chipsets, establishing the foundational reference design for Google’s device partners such as Samsung and LG.

We drove the full lifecycle of integration and validation: Starboard & Toolchain Modernization: Decoupled and restructured legacy Starboard recipes across RDK Yocto layers, modernizing toolchains to support newer C++ standards required by Chromium. Comprehensive Test Suite Integration: Integrated Chromium unit test suites alongside Starboard’s NPLB (No Platform Left Behind) conformance suite to ensure baseline platform compatibility. YTS Certification Enablement: Configured and validated the platform to pass the rigorous You Tube Test Suite (YTS) requirements, ensuring seamless 4K/UHD playback, DRM handling, and low-latency input.

RDK Ecosystem & Plugin Integration: Integrated Chrobalt into RDK’s modular plugin architecture (including RDK7 support), ensuring clean lifecycle management, memory sandboxing, and unified audio/video pipeline integration. Upstream Cobalt & Starboard Contributions: Identified and upstreamed critical fixes directly to the Cobalt/Starboard codebase to benefit the broader ecosystem. DAB Adapter & Test Automation: YTS runs are driven over the Device...