Horos

Horos is a high-performance, open-source 64-bit medical imaging viewer for macOS, built upon the established OsiriX framework. By 2026, it has maintained its status as the premier free alternative to enterprise-grade PACS workstations, widely utilized by radiologists, researchers, and veterinary practitioners globally. Its technical architecture leverages Apple's Cocoa framework and OpenGL for hardware-accelerated 3D rendering, enabling complex visualizations such as Multi-Planar Reconstruction (MPR), 3D Volume Rendering, and Maximum Intensity Projection (MIP). Horos distinguishes itself through a modular plugin architecture, allowing developers to extend its capabilities for specific clinical workflows or research needs. While the core software remains free under the LGPL license, it integrates seamlessly with Horos Cloud (powered by Purview) for cloud-based reporting, storage, and cross-institutional image sharing. As AI-driven diagnostics grow in 2026, Horos serves as a critical local validation node where clinicians can audit AI-generated segmentations and findings within a native DICOM environment, ensuring data integrity before final reporting.