History
Apple previously used a similar technique during the transition from 68k processors to PowerPC in the mid-1990s. These dual-platform executables were called fat binaries, referring to their larger file size.
NEXTSTEP, another predecessor of Mac OS X, supported the fat binary so that one application bundle could be run on multiple architectures, including Intel's x86, Sun Microsystems' SPARC and Hewlett-Packard's PA-RISC. The binary format underlying the universal binary, a Mach-O archive, is the same format used for the fat binary in NEXTSTEP.
Apple's Xcode 2.1 supports the creation of these files, a new feature in that release. A simple application developed with processor-independence in mind might require very few changes to compile as a universal binary, but a complex application designed to take advantage of architecture-specific features might require substantial modification. Applications originally built using other development tools might require additional modification. These reasons have been given for the delay between the introduction of Intel-based Macintosh computers and the availability of third-party applications in universal binary format. Apple's delivery of Intel-based computers several months ahead of their previously announced schedule is another factor in this gap.
Apple's Xcode 2.4 takes the concept of universal binaries even further, by allowing four-architecture binaries to be created (32- and 64-bit for both Intel and PowerPC), therefore allowing a single executable to take full advantage of the CPU capabilities of any Mac OS X machine.
Read more about this topic: Universal Binary
Famous quotes containing the word history:
“Spain is an overflow of sombreness ... a strong and threatening tide of history meets you at the frontier.”
—Wyndham Lewis (1882–1957)
“The visual is sorely undervalued in modern scholarship. Art history has attained only a fraction of the conceptual sophistication of literary criticism.... Drunk with self-love, criticism has hugely overestimated the centrality of language to western culture. It has failed to see the electrifying sign language of images.”
—Camille Paglia (b. 1947)
“You that would judge me do not judge alone
This book or that, come to this hallowed place
Where my friends’ portraits hang and look thereon;
Ireland’s history in their lineaments trace;
Think where man’s glory most begins and ends
And say my glory was I had such friends.”
—William Butler Yeats (1865–1939)