Horos (macOS)
Horos is a free DICOM viewer built for macOS. It was forked from the OsiriX project years ago and, since then, has become a go-to option for many clinics and universities that prefer Apple systems. The main reason it caught on is simple: it combines the features expected from a professional viewer with the freedom of open-source licensing. No dongles, no activation keys — just install it and start working.
Dental practices tend to use Horos for reviewing panoramic images and CBCT scans on Mac workstations. In academic settings, it often serves as the standard teaching tool because students can install it on their own laptops without cost barriers. IT staff like it too: deployment is straightforward, and once it’s in place, it rarely requires more than routine updates.
Core Characteristics
| Aspect | Details |
| Platform | macOS only (Intel and Apple Silicon supported) |
| File formats | Full DICOM support; export to JPEG, TIFF, QuickTime |
| Features | 2D and 3D visualization, multiplanar reconstruction, annotations, volume rendering |
| Interoperability | Works with PACS (DICOM query/retrieve); plugin support for extensions |
| Security | Relies on macOS environment and PACS-level authentication |
| Licensing | Open-source, free to use (LGPL) |
| Deployment model | Local installation, standalone workstation app |
Installation Guide
Download Horos – DMG installer available on the official site or GitHub.
Install on Mac – Drag to Applications folder. No license keys or activation.
Set up storage – Choose a directory for local DICOM data.
Connect to PACS (optional) – Enter server details, user credentials, and test connectivity.
Verify – Import sample datasets and check rendering in both 2D and 3D.
How It’s Used
– In a university dental lab, Horos is the tool students use to practice reading scans.
– In a private practice, it often runs on a consultation-room Mac so dentists can walk patients through imaging results.
– Research teams use it as a convenient way to open and inspect DICOM datasets before exporting them into other applications.
Deployment Notes
– Performance depends on the Mac hardware; newer GPUs handle CBCT volumes much better.
– Runs only on macOS — Windows and Linux are out of scope.
– Support comes from the open-source community; administrators often track updates directly from GitHub.
– Data should be backed up separately, as Horos itself doesn’t include archiving or replication tools.
Limitations
– macOS exclusivity may be a blocker for mixed-OS environments.
– Interface feels older compared to modern commercial solutions.
– No vendor-backed support contracts.
– Advanced PACS and security settings need manual fine-tuning.
Quick Comparison
| Tool | Distinctive Strength | Best Fit |
| Horos (macOS) | Free, open-source, native on macOS | Dental and medical users in Apple setups |
| OsiriX Lite | Commercial variant, vendor-backed | Mac users needing a supported product |
| Weasis DICOM Viewer | Cross-platform, PACS-integrated | Hospitals running mixed OS environments |
| RadiAnt DICOM Viewer (Trial) | Fast, Windows-based viewer | Clinics testing lightweight Windows tools |
