Gregory's ServerNot really "merge" so to speak, but you have the option of transferring from one to the other. You can fully interact with people on other servers, it just requires you to call out their full name versus just the handle. If you edit your profile and look at the very bottom, you have an option to move to a different account. That might be what you're looking for?
@IcicestTg
If you are the server admin on one/both of the servers you can look into setting up a relay between the two servers to mass transfer content.