it's created by the auth_signup module and it is used as a template when new users sign-up to openerp.

 <!-- Default template user for new users signing in -->
            <record id="default_template_user" model="res.users">
                <field name="name">Template User</field>
                <field name="login">portaltemplate</field>
                <!-- No password: this template user doesn't need to log in -->
                <field name="password"></field>
                <field name="active" eval="False"/>
                <!-- Avoid auto-including this user in any default group, just like a typical portal member -->
                <field name="groups_id" eval="[(5,)]"/>
            </record>