The Exporter module doesn't 'make things global', it gives you an easy way to export package variables and identifiers into the calling program -- the calling program may then use them directly (without qualification):

# calling program: foo.pl
#!/usr/bin/perl -w
use strict;
use MyPack;
print "$foo\n";
bar();
__END__


# module file: MyPack.pm
package MyPack;
require Exporter;
@ISA    = qw/Exporter/;
@EXPORT = qw/$foo bar/;
use strict;

$MyPack::foo = 42;
sub bar {
    print "This is MyPack::bar, who's calling please?\n";
}
1;
__END__


# example run:
[jandrew:~]$ perl foo.pl 
42
This is MyPack::bar, who's calling please?
[download]

So, Exporter is used to export things into the caller's namespace. Any package thingy in the package is always available to the caller if fully qualified. You may decide not to export anything (or only a few things) so as not to pollute the caller's namespace, or you may decide to export on demand (by using the @EXPORT_OK array instead) rather than exporting by default as the above example does (export on demand is often the better choice, so the caller gets to choose what to import into its namespace). Had I used the @EXPORT_OK array instead, then my calling program could have said: use MyPack qw/bar/;, and only the bar() routine would have been imported into its namespace (but the caller could still access $MyPack::foo).