ArcaOS 5.0 licenses may be upgraded to version 5.1. An upgrade includes a Support and Maintenance subscription. That subscription entitles the user to download the latest release of ArcaOS 5.1.
Current subscribers can upgrade their subscription at a lower price than expired subscribers. Current subscribers also get additonal months added to their subscriptions.
An ArcaOS 5.1 Support and Maintenance subscription is different than an ArcaOS 5.0 Support and Maintenance subscription. This is because some ArcaOS 5.1 content is only licensed for use with ArcaOS 5.1, so users who decide to wait to upgrade their licenses to ArcaOS 5.1 will get updates and support for ArcaOS 5.0 *only*. Likewise, there are components in ArcaOS 5.0 which will not ship with ArcaOS 5.1 (the current ArcaMapper GUI, for example). These updates would not be of any use to ArcaOS 5.1 licensees.
ArcaOS 5.1 upgrade for expired users is available in either personal or commercial editions. Personal edition upgrades come with a 6 months ArcaOS Support and Maintenance subscription. Commercial editions include prioritized support and a full year ArcaOS Support and Maintenance subscription.
One ArcaOS 5.1 license (new or upgrade) will entitle the customer to download the language of his choice. He may, in fact, subsequently download a different language. All available languages will be selectable from his download portal.
See ArcaOS FAQ for additional details.