Limit User Iinterface for Admin?

Question

Is there a plugin or a way where I can restrict or limit the buttons on the admin interface for a certain user?

For example:

• for the user who has a role of a writer, he/she can only post content,
  the other buttons are deactivated.

• for the designer he/she can only change the "Appearance Tab",
  all the others are deactivated.

Is there a solution for that?

Answer 1

Check out Adminimize, its done by Frank Bueltge a well known plugin author from germany. Link

Answer 2

Try something like this:

// function to remove the Links menu item
function wpse_7192_remove_menus()
{
    // setup the global menu variable
    global $menu;

    // this is an array of the menu item names we wish to remove
    $restricted = array( __('Links'));
    end ($menu);

    while (prev($menu))
    {
        $value = explode( ' ', $menu[key($menu)][0] );

        if( in_array( $value[0] != NULL ? $value[0] : "" , $restricted ) )
        {
            unset( $menu[key($menu)] );
        }
    }
}

if(!current_user_can('edit_pages'))
{
    // hook into the action that creates the menu
    add_action('admin_menu', 'wpse_7192_remove_menus');
}

That will remove the links menu for everyone except those that can manage options (which I believe is the Editor level).

So just follow this same logic to remove all the necessary menus for certain user levels.
Check out the post here for further details.