QEMC and Qlikview publisher are both different things.
QEMC and QMC can be defined as
They are two different consoles to manage all possible services and server settings. QEMC allows to to access to the webserver configuration, for example. Anyway, what you change in one console is kept in the other console, as the configuration files both read are the same. I'd say that QEMC is a more complete configuration console than the QMC. QEMC is used for Enterprise edition offering features such as unlimite document ,server based callibration,integration and third party security system and server clustering.It gives you full access to all possible setting for qlikview server.
QMC on the other handles only once instance of qlikview server.
PUBLISHER on the other hand is used for reduction,email and PDF and other important things..For detail you can go for the qlikview server refrence mannual...