ArcaOS
| ArcaOS 5.0.5 desktop | |
| Developer | Arca Noae, LLC (based on code from IBM, Microsoft, and other developers) | 
|---|---|
| Written in | C, C++, REXX, Java, assembly language | 
| OS family | OS/2 | 
| Working state | Current | 
| Source model | Closed source with open-source components | 
| Initial release | May 15, 2017 | 
| Latest release | 5.1.1 / February 16, 2025 | 
| Available in | English, German, Spanish, Russian | 
| Package manager | ANPM (based on RPM and YUM) | 
| Platforms | 32-bit x86 | 
| Kernel type | Hybrid kernel | 
| Default user interface | Workplace Shell, cmd | 
| License | Proprietary software | 
| Official website | www.arcanoae.com | 
ArcaOS is a proprietary operating system based on OS/2, developed and marketed by Arca Noae, LLC under license from IBM. It was first released in 2017 and builds on OS/2 Warp 4.52 by adding support for new hardware, fixing defects and limitations in the operating system, and by including new applications and tools, and includes some Linux/Unix tool compatibility. It is targeted at professional users who need to run their OS/2 applications on new hardware, as well as personal users of OS/2.
Like OS/2 Warp, ArcaOS is a 32-bit single user, multiprocessing, preemptive multitasking operating system for the x86 architecture. It is supported on both physical hardware and virtual machine hypervisors.