The following major changes have been made since John 1.6:

* Bitslice DES code for x86 with MMX: more than twice faster on Intel MMX.
* Bitsliced the LM hash code as well: now several times faster.
* Significant improvements to the generic bitslice DES code: +20% on RISC.
* PowerPC G4+ AltiVec support (Mac OS X only for now): effective 128-bitness
for bitslice DES, resulting in huge speedups.
* First attempt at generic vectorization support for bitslice DES.
* Two MD5 hashes at a time for extra ILP on RISC: up to +80% on Alpha EV5.
* Generic Blowfish x86 assembly code in addition to the original Pentium
version: +15% on the Pentium Pro family (up to Pentium III), +20% on AMD K6
(Pentium 4 and newer AMD CPUs are happy running the original Pentium code).
* Verbose logging of events to the global or a session-specific log file.
* Better idle priority emulation with POSIX.1b (POSIX.4) scheduling calls.
* System-wide installation support for *BSD ports and Linux distributions.
* AIX, DU/Tru64 C2, HP-UX tcb files support in unshadow.
* New make targets for Linux/x86-64, Linux/PowerPC, FreeBSD/Alpha, SCO,
OpenBSD/SPARC, OpenBSD/VAX, NetBSD/VAX, Solaris/SPARC64, Mac OS X, BeOS.
* Bug and portability fixes, and new bugs.
* Bonus: "Strip" cracker included in the default john.conf (john.ini).
