New Layers in Dynamics AX 2009http://blogs.msdn.com/mfp/archive/2008/04/22/new-layers-in-dynamics-ax-2009.aspx4 layers have been renamed in Dynamics AX 2009 . DIS / DIP / LOS / LOP have become HFX / SL1 / SL2 / SL3 respectively. HFX is reserved for releasing hot fixes, and the 3 new solution layers (SL1/SL2/SL3) will be used to release Microsoft Dynamics IndustryenCommunityServer 2.1 SP1 (Build: 61025.2)