Extensible Open Source Zero-Footprint Web Viewer for Cancer Imaging Research - Project Summary/Abstract The Open Health Imaging Foundation (OHIF) Viewer and its underlying libraries such as Cornerstone have become the standard framework for web-based imaging informatics technologies in cancer research and beyond, supporting hundreds of open-source projects with thousands of users. Through OHIF, developers can: 1) add new innovative tools as extensions to the OHIF Viewer; 2) use specific OHIF modules or libraries to build their own custom tools; and 3) web-enable existing desktop informatics platforms. To support the transition from desktop to web-based tools, researchers need well-supported frameworks to build upon. Currently, many cancer research image viewers require software to be installed on each user's local workstation, a drawback which limits accessibility and ease of collaboration. Most web-viewers available today are either proprietary, closed systems, or open-source research applications that use legacy technologies. For cancer imaging research that requires multi-site collaboration, there is a growing need for a framework that can enable researchers to review images and collaborate with colleagues remotely. OHIF’s zero-footprint web- viewer tools provide enormous usability benefits for end users, who gain instant access to view data across computers without any software to install or update. Under a prior NCI ITCR U24 grant, we developed the OHIF Framework, which provides a professional- grade, free, open-source web-based imaging environment for cancer research with image review, annotation functionality, and a user-friendly interface. The OHIF Viewer relies on standards, which has enabled easy integration with other systems, and it can be extended to provide custom functionality without modifying the core application. Additionally, its components can be re-used to rapidly develop new applications and help enable the transition to cloud computing for cancer research tools. The core goal of this proposal is to enhance and sustain the OHIF platform and broaden the user and contributor base of this technology. The current project has three aims: 1) extend the web-viewer’s cancer imaging visualization and analysis capabilities; 2) reduce barriers to adoption by creating ready-to-use installers for on-premises and cloud-hosted deployment; and 3) expand our support infrastructure for the cancer research community. For community support, we will enhance our outreach, engagement, and support initiatives to foster collaboration with developers and end users. In order to facilitate clinical translation and share our experience with regulatory compliance, we will implement a quality management system (QMS) for core OHIF framework development and regularly release design documentation to the community. Enhancing the platform's functionality, easing installation, and enriching support will allow researchers to better collaborate to evaluate the nature of cancer disease progression and response to treatment. With the widespread adoption of the OHIF platform to date, the impact of these improvements will be far reaching.