Difference between AntiCommandTab (BukkitDev) and AntiTab (Spigot)

Main.java

package De24.one;

import com.comphenix.protocol.ProtocolLibrary;
import com.comphenix.protocol.ProtocolManager;
import com.comphenix.protocol.events.ConnectionSide;
import com.comphenix.protocol.events.ListenerPriority;
import com.comphenix.protocol.events.PacketAdapter;
import com.comphenix.protocol.events.PacketContainer;
import com.comphenix.protocol.events.PacketEvent;
import com.comphenix.protocol.reflect.FieldAccessException;
import com.comphenix.protocol.reflect.StructureModifier;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.bukkit.entity.Player;
import org.bukkit.event.Listener;
import org.bukkit.plugin.Plugin;
import org.bukkit.plugin.java.JavaPlugin;

public class first extends JavaPlugin
  implements Listener
{
  ProtocolManager protocolManager;

  public void onEnable()
  {
    this.protocolManager = ProtocolLibrary.getProtocolManager();
    this.protocolManager.addPacketListener(new PacketAdapter(this, 
      ConnectionSide.CLIENT_SIDE, ListenerPriority.NORMAL, new Integer[] { Integer.valueOf(203) })
    {
      public void onPacketReceiving(PacketEvent event) {
        if (event.getPacketID() == 203)
          try {
            if (event.getPlayer().hasPermission("AntiTab.view"))
              return;
            PacketContainer packet = event.getPacket();
            String message = (String)packet.getSpecificModifier(String.class).read(0);
            if ((message.startsWith("/")) && (!message.contains(" ")))
              event.setCancelled(true);
          }
          catch (FieldAccessException e) {
            first.this.getLogger().log(Level.SEVERE, "Keine rechte fuer das Feld!", e);
          }
      }
    });
  }
}