In packaging transcode for macports, Chuck Remes noticed Apple's assembler is based on an outdated GNU assembler that doesn't support all the modern MMX, SSE2, SSE3, etc. extensions in open source applications. On OSX I have this: $ as -v Apple Computer, Inc. version cctools-622.5.obj~13, GNU assembler version 1.38 In contrast, Debian sid uses: # as -v GNU assembler version 2.17.50 (x86_64-linux-gnu) using BFD version (GNU Binutils for Debian) 2.17.50.20070426 The assembler is part of the binutils package, which is ported, but gas, the GNU assembler, is left out. Of course the Apple assembler supports all the modern extensions in their own software, but after GNU v1.28, Apple made the decision to move these binaries into their 'Accelerate framework' (http://developer.apple.com/performance/accelerateframework.html) -- as far as I understand as a part of their incremental moves to close the Darwin source. In the short run, and perhaps the long, this likely means we're not going to see free software's assembly code compile at all on OSX. Views? Dave