If you listen to much of the mac-buzz on the net, in the forums and IRC etc., you will see that many people seem sure that Mac OS X Build 4k78 (Sent to developers under the moniker "Release Candidate") is the build that was declared GM and released to manufacturing. I do not share this opinion. While I have no proof of this, I do have a few points to support this belief.
1) January 25, 2001 MacCentral reported that Shelia Annis, Apple's Mac OS product manager told them, "We have more surprises planned for the final version. "There is nothing that would really fall under that category in build 4k78 that we didn't already see at MacWorld San Francisco... And there has to be something new for Steve to demo at the Apple Event launching Mac OS X on March 21st.
2) 4k78 has programs ("Dock Extras") you put in the dock that act like control strip modules. There is one for adjusting monitor resolution and color depth, one that is a battery monitor and one that measures airport connection strength. It seems to me that a final release ought to at least have an easy way to adjust sound volume. Not to mention network settings, quick audio CD control, printer selection, microphone selection etc.
3) Build 4k78 lacks so many of the features of OS 9 and is so much slower than OS 9 that I can't imagine Steve would try to release the OS we have had to wait so long to get, the release he has been promising fixes everything that is wrong with Mac OS 8/9, in as incomplete a state as 4k78 is in. It is rumored that the 4k series of builds were designed strictly to give to their main developers. We know Steve Jobs hates it when his surprises get spoiled, and we know that prerelease versions of almost any Apple software get leaked all the time, primarily by Apple's 3rd party devs. It would seem a clever solution to the problem. Sure they still have the leaks, but are the leaks really showing anybody anything that Apple hasn't shown us already?
4) It seems unlikely Apple would leave a build number in the about this mac box in the final release. The final release ought just say either 1.0 or 10.0.
That being said 4k78 is the best build I have used to date by a long shot. I have found it to be stable compared to OS 9 or previous OS X builds. I experienced 1 crash in 5 days using it, and this was caused by Classic (Classic used to crash my computer almost once per sitting under public beta). I would estimate it to be overall at least twice as fast as the public beta. Unfortunately, it is significantly less snappy than OS 9. Everything in this build looks incredibly sharp. I'm not sure if this is just an improvement in font rendering as even outside of fonts everything else just looks very, very sharp. Anti-aliasing looks drastically better than it did in Public Beta or in OS 9.
The way the iDisk is integrated into the Finder is very functional and cool. However, one thing that is in 4k78 that I can't imagine Apple would let pass in a release version: When the finder is accessing an iDisk it ties up the Finder, giving you the colored pinwheel until it is done. You can still go into other applications and do things, but nothing else can be done with the Finder. In Internet Explorer 5.1 Preview when downloading a file all other IE functions become inoperative. As with the iDisk issue, the rest of the operating system (including other applications) are operable, but nothing else can be done in IE. This might lead one to believe that these bugs are an issue with Carbon, as I have yet to find a Cocoa app that does this.
While I don't see it to be of immense importance, much attention has been focused on live window resizing. Under 4k78 on an iMac DV SE (99) live window sizing in general has not attained the speed that we all hope for. Cocoa apps seem to have less trouble resizing, but it really mostly comes down to the complexity of the contents of the window. Unfortunately even with nothing in a window I think it could stand to get a bit snappier.
There have been a number of bug fixes and general optimizations since the builds seen around MacWorld San Francisco and Tokyo. There have also been a number of minor alterations and additions. USB devices work in Classic now, however the only Firewire device I have is a CD-Writer and it didn't work with Toast in Classic. It does work in OS X however... at least as a reader. Since I have no OS X native disc writing software (no, Apple's Disc Burner isn't included) I was unable to test writing in OS X. But my Handspring Visor Deluxe works via classic, my Kodak DC290 works in both classic and in the included OS X Image Capture application (Isn't it odd how Apple calls their program that goes out and grabs pictures off your camera "Image Capture", but calls the program that takes a capture of the image that is on your screen "Grab"), and my printer and scanner both work in Classic and OS X.
Text clippings finally work, though not precisely the same as in OS 9. If you drag selected text to the desktop you get a text file instead of an OS 9 style text clipping. Images show up as whatever image type they are and URL's still show up as bookmarks.
A very cool feature is that when you insert an audio CD the files show up as .aiff files and you can rip them just by dragging and dropping to your hard drive, just like you would any other file.
Another cool touch, when you resize the column view navigation services dialog it will come up at the same size the next time you save or open something. Each application retains it's own navigation services resizing information.
Quicktime 5 final is included, and it is excellent, performing as well as OS 9 QT, and in fact better when it comes to playing multiple .movs simultaneously. However MPEG performance is slightly better in OS 9. Unfortunately my Quicktime 4 SN didn't unlock saving and presenting movie, etc. so I couldn't see what all formats were available.
When you copy multiple files into a directory that contains a file of the same name as one of the files you are copying you are now given a new option in addition to stop and replace: Don't replace. This allows you to skip the file that already exists there, but copy the remaining ones.
You can quit an app from the dock. There is a new "Advanced" tab in the Classic System Preferences Panel that gives you the ability to start without extensions, start into Extensions Manager, assign keys for Classic shutdown and restart, set the delay until Classic goes to sleep and to rebuild Classic's desktop file.
Unfortunately there are few notable things left out of this build, such as spring-loaded folders, sound sets, or patterns as desktop images. There is also an odd bug I noticed: When you look at your files in a "by name" view normally a leading space causes a file to be listed higher than a leading A. However in the docks hierarchical listing of a folder leading spaces are ignored. So if you have used spaces to organize files in list view, it will be all messed up when accessed from the dock.
One of the most impressive features of this build is the fact that when you press the numlock key on an extended keyboard, the numlock light actually lights! ;^) Another great one is the ability to change the time in the Date and Time panel by moving the hour and minute hands.
All in all I am thrilled to use this build. I will not likely ever return to OS 9. But I fear most users would not be happy with this build, and thus my concern over it's reputation as the GM. Though the media will likely pulverize Apple for this builds shortcomings if this is truly the GM, at least they won't be shipping it preinstalled on machines until version 1.1 is released. This build gives the impression that with just a tiny bit more time OS X can be near-perfect.
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