PROJECT SUMMARY The Mobilize Center is a Biomedical Technology Resource Center (BTRC) with the goals of creating and disseminating innovative tools to quantify movement biomechanics with mobile technologies and deliver personalized mobile health rehabilitation programs. One of the Center’s new tools is OpenCap, which enables researchers to quantify and analyze the biomechanics of 3-D human movement from smartphone videos. This free, cloud-based tool was released in July 2022. It is already in use by more than 1,500 biomechanics researchers and has compiled data from more than 40,000 motion capture trials. As a BTRC, the Mobilize Center also has training and dissemination aims, including an aim to create and maintain data-sharing communities to accelerate research. Data-sharing is particularly impactful when it comes to deep learning applications with their need for large datasets. OpenCap lowers the barrier for communities to collect and process motion data, and therefore, presents an opportunity to simultaneously advance the Mobilize Center’s data-sharing aim. However, OpenCap’s primary purpose is data collection and not data sharing. It lacks key features for open data sharing and scientific reproducibility, such as a mechanism to associate metadata, search and filter datasets to download, link data to publication(s), register the data, and provide a permanent reference (e.g., a DOI) to the data. Rather than reinventing the wheel for these features, we will leverage SimTK, an online platform designed to promote open science. SimTK is a web-based software, model, and data-sharing repository for the biocomputational community with over 130,000 members. Specifically, we will make OpenCap interoperable with SimTK by: 1) Integrating OpenCap and SimTK to support full-featured video and motion data sharing, so that OpenCap datasets can take advantage of SimTK functionality to promote open science, and 2) Extending SimTK’s API to enable OpenCap to collect standardized metadata. Achieving these aims will expand the impact of our data-sharing aim, make OpenCap more widely used, and increase the number, diversity, findability and re-usability of OpenCap’s datasets.