Upgrading from:

DiscreteMath`IntegerPartitions`

DiscreteMath`IntegerPartitions` was available as an add-on package in previous versions of Mathematica and is now available on the web at library.wolfram.com/infocenter/MathSource/6762.
The functionality of IntegerPartitions can be obtained using the new kernel function IntegerPartitions.

Construct a restricted partition:

Version 5.2 << DiscreteMath`IntegerPartitions`
IntegerPartitions[5, 3]