A.13.2 Between Versions 1 and 2
• 260 new built-in objects have been added, some of whose names may conflict with names already being used.
• Accumulate has been superseded by FoldList; Fold has been added.
• Condition (/;) can now be used in individual patterns as well as in complete rules, and does not evaluate by default.
• The functionality of Release has been split between Evaluate and ReleaseHold.
• Compose has been superseded by Composition.
• Debug has been superseded by Trace and related functions.
• Power no longer automatically makes transformations such as Sqrt[x^2]x.
• Limit now by default remains unevaluated if it encounters an unknown function.
• Mod now handles only numbers; PolynomialMod handles polynomials.
• CellArray has been superseded by Raster and RasterArray.
• FontForm takes a slightly different form of font specification.
• Framed has been superseded by Frame and related options.
• ContourLevels and ContourSpacing have been superseded by Contours.
• Plot3Matrix has been superseded by ViewCenter and ViewVertical.
• FromASCII and ToASCII have been superseded by FromCharacterCode and ToCharacterCode respectively.
• Alias has been superseded by $PreRead.
• ResetMedium has been subsumed in SetOptions, and $$Media has been superseded by Streams.
• StartProcess has been superseded by Install and by MathLink.
• Additional parts devoted to Mathematica as a programming language, and to examples of Mathematica packages, have been dropped from The Mathematica Book.