Why do Netlink, Genexis ONTs have similar looking user interface

[parkerpeter]

Why do Netlink, Genexis ONTs have similar looking user interface?
Is this because both use same 3rd party for developing their firmware or are they using some open source code?

 

[vishalrao]

They're all likely using the same cheap Chinese chipset vendor like ZTE that comes with same standard firmware which these brands don't bother to customise.