How to connect to a named SQL Server instance without specifying its name? Is there anyway I can connect to a SQL server that has no default instance, using just the server name? I've tried using SQL CMD, but it seems that the named instance name is required to login, regardless? Does anyone know how this could be acheived and what language?
If there is no default instance, then you could force the named instance to listen on port 1433.  SQL Server Configuration Manager, then navigate to the networking bit and turn off dynamic ports.  

This article goes into details on how you can do that for multiple instances running on the same server, but it gets complicated fast.  How to Add a Hostname alias for a SQL Server Instance.  

So there are the methods, but why do you want to do it that way?