DFSORT can be invoked using PGM=ICEMAN or PGM=SORT (they are equivalent).
ICETOOL is a utility that has been shipped with DFSORT since 1991. ICETOOL can be invoked using PGM=ICETOOL.
If you're not familiar with DFSORT and DFSORT's ICETOOL, I'd suggest reading through "z/OS DFSORT: Getting Started". It's an excellent tutorial, with lots of examples, that will show you how to use DFSORT, DFSORT's ICETOOL and DFSORT Symbols. You can access it online, along with all of the other DFSORT books, from: