Random notes from a security-aware software engineer, open-source advocate and occasional lecturer.
Proxmox is free software and can be used without acquiring a license. But there are commercial subscriptions for enterprise repositories available. These provide not only access to the repository, but also additional support.
If you use Proxmox for production, please consider getting a subscription. Not only will you get support if necessary, but you also help to sustain the project.
If you use Proxmox without subscription, you will get a notice whenever you log in. Usually, you can just ignore this. Nevertheless, this might be annoying in a few cases. John McLaren published a way to simply remove the notification without subscription.
In short, just run:
Of course, this is not officially supported and may stop working at any time.