Metal (Metallicus Inc) the core developer is already generating revenue today with a functional licensed MSB and exchange in the United States (metalpay.com) which is soon integrating Proton blockchain as its core backbone for noncustodial transfers, identity, and signing. Source: over 2 years ago

Maybe you should check the metal (MTL) project and the proton (XPR) blockchain. With their app you can basically give your wallet a human name within their blockchain. Source: about 3 years ago

Metalpay.com shows that BNB is an "available crypto" so I'd go with this option^. Source: about 3 years ago

OpenBravo POS used to be ok, it even worked with barcode readers. But you could also manually punch up a sales receipt and it would adjust on hand numbers automatically. But Open Bravo has moved on to a cloud paid model. However there a few forks from the before time, like Unicenta, but I've never used that one and can only vouch for what it was back in the day. Source: over 2 years ago

I would recommend going with https://opensourcepos.org/ or https://unicenta.com/. Source: almost 3 years ago

Unicenta works pretty well on a POS that I salvaged from a shop closure last year (no reason for doing so - just thought it would be cool to have one for the hell of it). Runs on Linux as well as Windows if you want to escape Windows Embedded 7. Source: almost 3 years ago

Looks like Unicenta is an alternative POS that can be self-hosted and is licensed as GPL-3.0-or-later. Source: about 3 years ago