Mac users-- The latest nightly version of Phenix (dev-532) is now capable of compiling 64-bit objects on Snow Leopard, which should help those of you working on very large and/or high-resolution structures. You will need to use the source installer for this; it will automatically recognize the machine type as "mac-intel-osx-x86_64" and use the correct sources. There are several things to be aware of before trying this: 1. I had to switch to the development version of wxPython to get the GUI working, and it's both inherently less stable and based on fundamentally different OS libraries, which may cause problems. I've fixed some of the most obvious issues and everything appears to run now, but I expect to find more glitches. (This shouldn't affect command-line users.) 2. We haven't extensively tested 64-bit Phenix on Mac; there may be undiagnosed low-level bugs, even for command-line-only use. This should change soon. 3. For the above reasons, and because source installation is generally difficult to support, we recommend that you continue to use the 32-bit binary installer if you are not experiencing memory problems. (It will figure out what you are trying to do and correct the machine type accordingly.) 4. One side effect of this change is that an installation made on Leopard will not work on Snow Leopard, and vice-versa. I may be able to fix this. Hopefully there will be a binary installer in the near future, if I can ever figure out how to fix NFS on my workstation. -Nat