Hi Arwid, Yes Chimera 1.4 released in December of 2009 is the last Chimera version that is compatible with Mac OS 10.4, both PPC and Intel. This is mentioned in the News column on the Chimera web page (Dec 3, 2009). We will have a Chimera 1.4.1 release to fix some bugs around the end of this month that will work with Mac OS 10.4. The Chimera package you mentioned is our daily development build version 1.5 and was built using Mac OS 10.5. We are updating Chimera to use the new Mac Tk windowing library based on Cocoa so that we can provide a 64-bit version of Chimera for users with large data sets. Tk Cocoa only runs on Mac OS 10.5 and later. The older Mac Tk using the Mac Carbon library (32-bit only) will no longer be maintained by Daniel Steffen the main Mac Tk developer. We are not yet certain if both 32-bit and 64-bit versions of Mac Chimera 1.5 will use Tk Cocoa. The 64-bit has to, and we would like the 32-bit version to use the same Tk library. Whether we use the old Tk Carbon for 32-bit Chimera depends on whether we encounter any serious deficiencies in Tk Cocoa. So far it looks like Tk Cocoa will work for both 32-bit and 64-bit Chimera on the Mac. A second reason for requiring Mac OS 10.5 for future Chimera versions is that it is trouble for us to keep very old computers in the lab. We have two Mac OS 10.4 systems (PPC and Intel) in our lab that are only used for Chimera builds. We would like to retire those old systems. While it is possible to build on Mac OS 10.5 a binary that will run on Mac OS 10.4 we have tested that and encountered problems. Tom

Ldies and Gentlemen,

The Chimera version

Mac OS X (Aqua, PowerPC) chimera-alpha-osx_ppc_aqua.dmg <https://www.cgl.ucsf.edu/cgi-bin/chimera-get.py?file=alpha/chimera-alpha-osx_ppc_aqua.dmg> Size: 73241868 bytes MD5: 39623fa9e0d9f4a869a4c985d45223bb Jan 22, 2010

is not compatible with G4 PPC Mac OS 10.4.11.

Do you plan to quit the G4 PPC OS 10.4.11. - Compatibility ????

With best regards,

Dr. Arwid Biebach, Germany