morebits
uselargefiles
usesocks (only SOCKS v5 supported)
Threadedness and 64-bitness now more daring
The Configure options enabling the use of threads and the use of 64-bitness are now more daring in the sense that they no more have an explicit list of operating systems of known threads/64-bit capabilities. In other words: if your operating system has the necessary APIs and datatypes, you should be able just to go ahead and use them, for threads by Configure -Dusethreads, and for 64 bits either explicitly by Configure -Duse64bitint or implicitly if your system has 64-bit wide datatypes. See also "64-bit support".
Long Doubles
Some platforms have "long doubles", floating point numbers of even larger range than ordinary "doubles". To enable using long doubles for Perl's scalars, use -Duselongdouble.
-Dusemorebits
You can enable both -Duse64bitint and -Duselongdouble with -Dusemorebits. See also "64-bit support".
-Duselargefiles
Some platforms support system APIs that are capable of handling large files (typically, files larger than two gigabytes). Perl will try to use these APIs if you ask for -Duselargefiles.
See "Large file support" for more information.
installusrbinperl
You can use "Configure -Uinstallusrbinperl" which causes installperl to skip installing perl also as /usr/bin/perl. This is useful if you prefer not to modify /usr/bin for some reason or another but harmful because many scripts assume to find Perl in /usr/bin/perl.
SOCKS support
You can use "Configure -Dusesocks" which causes Perl to probe for the SOCKS proxy protocol library (v5, not v4). For more information on SOCKS, see:
http://www.socks.nec.com/
-A flag
You can "post-edit" the Configure variables using the Configure -A switch. The editing happens immediately after the platform specific hints files have been processed but before the actual configuration process starts. Run Configure -h to find out the full -A syntax.
Enhanced Installation Directories
The installation structure has been enriched to improve the support for maintaining multiple versions of perl, to provide locations for vendor-supplied modules, scripts, and manpages, and to ease maintenance of locally-added modules, scripts, and manpages. See the section on Installation Directories in the INSTALL file for complete details. For most users building and installing from source, the defaults should be fine.
If you previously used Configure -Dsitelib or -Dsitearch to set special values for library directories, you might wish to consider using the new -Dsiteprefix setting instead. Also, if you wish to re-use a config.sh file from an earlier version of perl, you should be sure to check that Configure makes sensible choices for the new directories. See INSTALL for complete details.
Platform specific changes
Supported platforms
VM/ESA is now supported.
Siemens BS2000 is now supported under the POSIX Shell.
The Mach CThreads (NEXTSTEP, OPENSTEP) are now supported by the Thread extension.
GNU/Hurd is now supported.
Rhapsody/Darwin is now supported.
EPOC is is now supported (on Psion 5).
The cygwin port (formerly cygwin32) has been greatly improved.
DOS
Perl now works with djgpp 2.02 (and 2.03 alpha).
Environment variable names are not converted to uppercase any more.
Incorrect exit codes from backticks have been fixed.
This port continues to use its own builtin globbing (not File::Glob).
OS390 (OpenEdition MVS)
Support for this EBCDIC platform has not been renewed in this release. There are difficulties in reconciling Perl's standardization on UTF-8 as its internal representation for characters with the EBCDIC character set, because the two are incompatible.
It is unclear whether future versions will renew support for this platform, but the possibility exists.
VMS
Numerous revisions and extensions to configuration, build, testing, and installation process to accomodate core changes and VMS-specific options.
Expand %ENV-handling code to allow runtime mapping to logical names, CLI symbols, and CRTL environ array.
Extension of subprocess invocation code to accept filespecs as command "verbs".
Add to Perl command line processing the ability to use default file types and to recognize Unix-style 2>&1.
Expansion of File::Spec::VMS routines, and integration into ExtUtils::MM_VMS.
Extension of ExtUtils::MM_VMS to handle complex extensions more flexibly.
Barewords at start of Unix-syntax paths may be treated as text rather than only as logical names.
Optional secure translation of several logical names used internally by Perl.
Miscellaneous bugfixing and porting of new core code to VMS.
Thanks are gladly extended to the many people who have contributed VMS patches, testing, and ideas.
Win32
Perl can now emulate fork() internally, using multiple interpreters running in different concurrent threads. This suppo
