The Developer Utilities Package includes functions that directly access specific internal algorithms and capabilities of the Wolfram Language that are normally used only as part of more general functions.

$MaxMachineInteger — maximum integer represented as an atomic data element

MachineIntegerQ — whether a number is represented as a machine-size integer

BesselSimplify — transform Bessel functions in an expression

GammaSimplify — transform gamma functions

PolyGammaSimplify — transform polygamma functions

ZetaSimplify — transform zeta functions

PolyLogSimplify — transform polylogarithm functions

TrigToRadicals — convert trigonometric functions to radicals in an expression

ToPackedArray — convert the internal representation of an expression to a packed array

FromPackedArray — unpack a packed array

PackedArrayForm — print packed arrays in summary form

PackedArrayQ — whether an expression is a packed array of an optionally given type

Notebook Manipulation

CellInformation — information about selected cells in a given notebook object

NotebookConvert — convert a notebook from a legacy version of Mathematica

ReplaceAllUnheld — apply rules to parts of an expression that would be evaluated