Transaction fee schedule has been modified. Most transactions are free if they are less than 2000 bytes in size, have enough coin age and don't get caught by the dust spam filter (any output < 0.01 PXC). A regular transaction (1 input, 1 output) is 192 bytes. The minimal transaction fee is unchanged at 0.1 PXC for those transactions which require a fee.
Another important improvement is a soft fork at block #270000 which enables a better protection against time travel attacks and the block limiter against hostile coin hoppers (no more than 6 blocks per 2 minutes can be accepted). There are also a few important security fixes.
This is the 1st time we offer an official client for MacOS X (both 32-bit and 64-bit versions supported, 10.5+). A 32-bit Linux build (i386) is also available in addition to the 64-bit one (amd64). As usual, 32-bit and 64-bit Windows builds.