ESP-Miner and AxeOS are licensed GPLv3. That often gets described as a control mechanism, but it's quite the opposite.
The license does one thing: it keeps the source open when the code changes hands.
Under private use, there is nothing required. Your changes and customization are yours, and they stay that way as long as you want.
The one requirement applies at distribution. Sell or distribute hardware with modifications preloaded and you publish the source alongside it. That person then has what you had, which is working code they can read and build on.
This is why home mining has a learning curve people can actually climb. Every improvement to ESP-Miner stays readable, which means the next person does not start from zero. They start from working code written by someone who solved the problem first. Frequency tuning, thermal handling, Stratum behavior, power curves. All of it is out in the open to study, question, and improve.
It is also why the pace of improvement has been what it is. Hundreds of contributors have shipped features into this firmware because the ceiling on contributing is reading the code rather than signing an agreement. Closed firmware caps innovation at whatever one company decides to fund. Open firmware does not have that ceiling.
Open firmware keeps mining itself transparent. You can verify what your hardware is doing. Where it points, what it reports, what it sends. Nobody has to take that on trust, which is the whole principle the network runs on. Don't trust, verify applies to the firmware too.
The GPLv3 is not a limit on hobbyists or tinkerers. It is what keeps community work from being taken, closed, and sold back.
