Comment 4 for bug 525523

Here's the FPC upstream changelog:

******************************************************************************
                              What's New in 2.4.0
******************************************************************************

Free Pascal 2.4.0 contains many fixes and new features. While we did not
manage to incorporate all planned additions, we believe this release offers a
nice collection of new functionality and bug fixes.

Please also see http://wiki.freepascal.org/User_Changes_2.4.0 for a list
of changes which may affect the behaviour of previously working code, and
how to cope with these changes.

Some highlights are:

Platforms:
  * New platform: Mac OS X/PowerPC64
  * New platform: Mac OS X/x86_64
  * New platform: Mac OS X/ARM (iPhone)
  * New platform: Haiku/i386

Compiler:
  * Support for Delphi-style resource handling
  * Whole-program optimization infrastructure, which initially supports
    program devirtualization and unused virtual method removal
  * Much faster compilation of units containing many type-sections
  * The ability to suppress individual hints/warnings/notes
  * Several improvements to the DWARF debug information generation
  * Fixes to the generics support
  * Fixes to the interface delegation (implements) support
  * Improved cpu register allocation
  * Improved ARM/EABI support

RTL:
  * Linearly scaling multi-threaded memory manager
  * Support for (advisory) file locking on Unix-based platforms
    when using the SysUtils file creation/opening routines
  * Support for ANSI ISO Extended Pascal ReadStr/WriteStr
  * A UnicodeString type that, while not yet equivalent to Delphi 2009's
    UnicodeString type, offers reference counted UnicodeString support on
    the Windows, Linux, Mac OS X, FreeBSD and Beos/Haiku platforms.

Packages:
  * Many improvements to the XML units
  * Many improvements to the database units
  * Updated the common Mac OS X Pascal interfaces to r241, including
    header a translation of the CFNetwork framework
  * The zipper unit now works correctly on big endian platforms

See http://bugs.freepascal.org/changelog_page.php for the list of reported
bugs which have been fixed in this release.