diff --git a/YACOSCore/ejbModule/org/yacos/core/Conference.java b/YACOSCore/ejbModule/org/yacos/core/Conference.java
deleted file mode 100644
index 99010e0..0000000
--- a/YACOSCore/ejbModule/org/yacos/core/Conference.java
+++ /dev/null
@@ -1,12 +0,0 @@
-/**
- * 
- */
-package org.yacos.core;
-
-/**
- * @author christiancorsano
- * TODO
- */
-public class Conference {
-
-}
diff --git a/YACOSCore/ejbModule/org/yacos/core/Role.java b/YACOSCore/ejbModule/org/yacos/core/Role.java
deleted file mode 100644
index e5cca91..0000000
--- a/YACOSCore/ejbModule/org/yacos/core/Role.java
+++ /dev/null
@@ -1,66 +0,0 @@
-package org.yacos.core;
-
-/**
- * An role of a given type (author,chairman,PCmember or referee)
- * defined for a user and a conference
- * @author christiancorsano
- *
- */
-public class Role {
-	/**
-	 * User for which this role is defined
-	 */
-	private User user;
-	/**
-	 * Conference for which this role is defined
-	 */
-	private Conference conference;
-	/**
-	 * The type of this role
-	 */
-	private RoleType type;
-	
-	public Role(RoleType type,User user, Conference conference) {
-		super();
-		setType(type);
-		setUser(user);
-		setConference(conference);
-	}
-	/**
-	 * @return the user who plays this role
-	 */
-	public User getUser() {
-		return user;
-	}
-	/**
-	 * @param user the user who is to play this role
-	 */
-	public void setUser(User user) {
-		this.user = user;
-	}
-	/**
-	 * @return the conference for which this role is defined
-	 */
-	public Conference getConference() {
-		return conference;
-	}
-	/**
-	 * @param conference the conference for which this role is defined
-	 */
-	public void setConference(Conference conference) {
-		this.conference = conference;
-	}
-	/**
-	 * @return the type of this role
-	 */
-	public RoleType getType() {
-		return type;
-	}
-	/**
-	 * @param type the type of this role
-	 */
-	public void setType(RoleType type) {
-		this.type = type;
-	}
-	
-}
diff --git a/YACOSCore/ejbModule/org/yacos/core/RoleType.java b/YACOSCore/ejbModule/org/yacos/core/RoleType.java
deleted file mode 100644
index cfb7b6d..0000000
--- a/YACOSCore/ejbModule/org/yacos/core/RoleType.java
+++ /dev/null
@@ -1,48 +0,0 @@
-/**
- * 
- */
-package org.yacos.core;
-
-/**
- * @author christiancorsano
- *
- */
-public class RoleType {
-	/**
-	 * Author constant role
-	 */
-	static public final RoleType author = new RoleType("author");
-	/**
-	 * Chairman constant role
-	 */
-	static public final RoleType chairman = new RoleType("chairman");
-	/**
-	 * PCMember constant role
-	 */
-	static public final RoleType PCmember = new RoleType("PCmember");
-	/**
-	 * Referee constant role
-	 */
-	static public final RoleType Referee = new RoleType("referee");
-	
-	/**
-	 * Name of this role type
-	 */
-	private String name;
-	
-	/**
-	 * Private constructor : used to instanciate the constants
-	 * @param name Name of the new RoleType
-	 */
-	private RoleType(String name){
-		this.name = name;
-	}
-	
-	/**
-	 * Return the name of this RoleType
-	 * @return
-	 */
-	public String getName() {
-		return this.name;
-	}
-}
diff --git a/YACOSCore/ejbModule/org/yacos/core/User.java b/YACOSCore/ejbModule/org/yacos/core/User.java
deleted file mode 100644
index 1ef4cfe..0000000
--- a/YACOSCore/ejbModule/org/yacos/core/User.java
+++ /dev/null
@@ -1,104 +0,0 @@
-package org.yacos.core;
-
-import java.util.Set;
-
-/**
- * A unique User of the system.
- * The user is registered globally in the application and would be able to get different roles for
- * different conferences.
- * @author christiancorsano
- *
- */
-public class User {
-	/**
-	 * Unique login of the user
-	 * Is used to identify the user, should be unique and can't be modified
-	 */
-	private String login;
-	/**
-	 * Password : used for authentication purpose only, is only writable
-	 */
-	private String password;
-	/**
-	 * First Name of the user
-	 */
-	private String firstName;
-	/**
-	 * Last name of the user
-	 */
-	private String lastName;
-	/**
-	 * Organization or lab the user belongs to
-	 */
-	private String organization;
-	/**
-	 * Active email (has to be used frequently) of the user
-	 */
-	private String email;
-	
-	public User() {
-		
-	}
-
-	public String getLogin() {
-		return login;
-	}
-	
-	public void setPassword(String password) {
-		this.password = password;
-	}
-
-	public String getFirstName() {
-		return firstName;
-	}
-
-	public void setFirstName(String firstName) {
-		this.firstName = firstName;
-	}
-
-	public String getLastName() {
-		return lastName;
-	}
-
-	public void setLastName(String lastName) {
-		this.lastName = lastName;
-	}
-
-	public String getOrganization() {
-		return organization;
-	}
-
-	public void setOrganization(String organization) {
-		this.organization = organization;
-	}
-
-	public String getEmail() {
-		return email;
-	}
-
-	public void setEmail(String email) {
-		this.email = email;
-	}
-	
-	public void addRole(Role role){
-		// TODO
-	}
-	
-	public void addRoleForConference(RoleType roleType, Conference conference){
-		if(! hasRoleForConference(roleType)){
-			
-		} else {
-			// TODO : declare and throw an exception
-		}
-	}
-	
-	public boolean hasRoleForConference(RoleType roleType){
-		// TODO
-		return false;
-	}
-	
-	public Set<Role> getRoles(){
-		// TODO
-		return null;
-	}
-}
diff --git a/YACOSCore/ejbModule/org/yacos/core/UsersManager.java b/YACOSCore/ejbModule/org/yacos/core/UsersManager.java
deleted file mode 100644
index d54c844..0000000
--- a/YACOSCore/ejbModule/org/yacos/core/UsersManager.java
+++ /dev/null
@@ -1,33 +0,0 @@
-/**
- * 
- */
-package org.yacos.core;
-
-import java.util.Collection;
-
-/**
- * @author christiancorsano
- *
- */
-public class UsersManager {
-	public Collection<User> getUsers(){
-		// TODO
-		return null;
-	}
-	
-	/**
-	 * Adds a user into the system
-	 * @param user
-	 */
-	public void addUser(User user){
-		// TODO
-	}
-	
-	/**
-	 * Removes a user from the system
-	 * @param user
-	 */
-	public void removeUser(User user){
-		// TODO
-	}
-}