You must register to be able to use SIDE Enterprise Edition, except SIDE/Labs which is distributed under an open source license.
In the register form in SIDE, under Eclipse/Preferences, you'll be asked for a field named "Unique ID":
Once registered, you will be able to connect on the login page.
Once logged, you can ask a key for SIDE Enterprise Edition (SIDE-Alfresco, SIDE-Prototype, ...) and edit your profile.
Generated keys will be sent to you by mail. You can then insert the key in the Licence Key page in SIDE, under Eclipse/Preferences.

If your key is valid, you will see the date until your key is operational, and all its components.
