In NSW we can use preschool which is usually run by council or community/church run. Its usually for a maximum of 3 days per week. Long daycare often offers a preschool program too.
Preschool is not compulsorary in NSW but the majority of children do seem to do some kind of preschool before they start school. As a teacher you really notice the difference between kids who have had no preschool/daycare experience and those who have.
I think it is so ridiculous that each state has their own system. I taught in NT and they have different starting to here, different curriculum and handwriting style too. Its one of my pet hates, I am all for a standard education system across the whole of Australia.