Built heavily with code from https://github.com/Ygnecz/MTLic.
This tool can generate structurally valid RouterOS license keys. Being valid only structurally doesn't necessarily mean you can just run this and use the generated key on your MikroTik router or whatever device you're running RouterOS on. In order for RouterOS to consider a license fully valid, it has to be digitally signed with a private key (that only MikroTik knows). For more info about how impenetrable this is, search "digital signatures" on Google.
If, in your RouterOS installation, you replace MikroTik's public key with the one that is outputted by this tool, then yes, the license key will be fully valid, but only for your installation, obivously.
This is the first time I go this deep with digital signing since MikroTik's signing-verifying procedures seems to be not so standard, so please don't judge :)
Everything is for educational purposes only. Neither I managed to actually use any license generated by this, yet.