ArcaOS 5.1 is not available for free as it is a commercial operating system developed and sold by Arca Noae. While there is no "free trial" or public free download for the full OS, certain users may be eligible for a no-cost download under specific conditions. How to Obtain ArcaOS 5.1
Why you should avoid “free download” kits
. After purchase, a personalized ISO image is built for you and made available for download New Licenses : Available for purchase as Personal or Business editions arcaos 51 download free
If you are looking for a free alternative in the OS/2 ecosystem, you might consider FreeOS/2, though it is far less compatible with modern hardware and software than ArcaOS.
Searching for a "free download" of ArcaOS 5.1 is a common trap. While the underlying OS/2 legacy is historic, ArcaOS is commercial software and is not available for legal free download. ArcaOS 5
ArcaOS 5.1: Is There a Free Download? (What You Need to Know)
Official Source: The only authorized place to download the software is through your personal customer portal on the Arca Noae website after purchasing a license. After purchase, a personalized ISO image is built
Commercial Edition: Approximately $249.00 (includes 1 year of priority support).