This is a great improvement on efficiency and contributes to better privacy. Full fledged multidimensional arrays. Any scalar value, including an array element, may now contain a reference to any other variable or subroutine. Easily created anonymous variables and subroutines. The Perl library is now defined in terms of modules which can be easily shared among various packages.
Packages can import any or all of a module's published interface.
Dynamic multiple inheritance and virtual methods are supported in a straight-forward manner with little new syntax. Filehandles are now treated as objects. Dynamic loading of modules is supported. The dbmopen interface has been generalized to allow any variable to be tied to an object class which defines its access methods. Embedded whitespace and comments for readability.