It's not 09 it is Series 9 (Subtype, sorta)

VB.net 2008 is the 9th installment of the VB series

Vb 1, 2 , 3, 4, 5, 6

Then Came VB.net 2003 which was VB 7

Then VB.net 2005 which was VB 8 (the 8th installment)

and so on