OpenStep Overview
Volume Number: 13
Issue Number: 3
Column Tag: Rhapsody
A Quick Take On Apple's Purchase Of NeXT
By Dave Klingler
What are the pros and cons of Apple's integration of NeXT
technologies with the MacOS
A Late 1996 Christmas Present for the Rest of Us
My first reaction to the news of NeXT's sale to Apple was a groan of despair. For those
who don't remember, Steve Jobs used to make having an Apple computer a roller
coaster ride. Having anything at all to do with NeXT was the same way. Steve doesn't
believe in color, floppy disks, games or self-restraint when it comes to offending the
entire computer industry.
When I found out that Steve would be strictly an adviser to Amelio and Roizen, I
breathed a cautious sigh of relief. I have met Steve Jobs and spoken to him twice. My
personal reaction was that he was an individual of very high integrity and strong
convictions, and I liked him a great deal. Steve can sometimes be right on when
devising "insanely great" technologies. You can get an idea what life is like for me when
you consider that I'm addicted to using my monochrome cube. Pain and pleasure all
mixed into one.
I think the best thing to come out of the deal is that Apple will get Avi Tevanian, and,
presumably, Jean-Marie Hullot. Tevanian did much of the original Mach port to the
NeXT platform, and Hullot wrote a fair portion of the NeXT operating system and
Interface Builder. I'd gladly work for Apple if it meant a chance to work with either
one of these two guys. I've developed a strong respect for the rest of NeXT's software
engineers as well.
If Apple slashes the cost of NeXT's products, such as the OS and WebObjects, I will be
overjoyed. The products are superior, and their new lease on life would mean that I
don't have to switch platforms for a while longer. NeXT's OS is arguably the most
immediately relevant part of the deal for Mac developers, so I'm going to tell some of
what I know about it.
OpenStep's Strengths
As most any Mac developer knows by now, Apple spent some time considering a number
of options for the development of the next MacOS. These included purchase or
integration of BeOS, Solaris or NeXT's OpenStep for Mach.
OpenStep for Mach (formerly called NeXTStep) is in many ways a far more elegant OS
than the BeOS. It is based on the Mach microkernel with a BSD 4.4 personality for
unix compatibility. The Display Postscript (DPS) server is tightly integrated into the
OS just on top of the kernel, and so is Objective C. What makes OpenStep for Mach sort
of magical is the sum of its parts: Mach + DPS + Objective C = an extremely elegant
development environment. I'll refer to it from this point on as OpenStep, but keep in
mind that the development environment has been decoupled from the OS and is
available as OpenStep for Windows NT and Solaris as well.
For those of you who might be worried about DPS's speed, it's not really an issue. NeXT
and Adobe optimized the DPS server so well that one never sees any sort of redraw.
Note that I said "server"; DPS is a client-server system, so you can host a display on a
different system than the one that's actually doing the drawing calculations.
The Mach microkernel is a multiprocessor-capable threading OS kernel. It has been
ported to almost every processor extant, one of those being the PowerPC. Anyone who
does NT development will notice that the NT kernel API is almost identical to Mach's,
other than the Graphics Device Interface (NT's GDI was recently tied into the kernel in
a controversial move by Microsoft to make NT faster for everyday users, thus
changing the NT kernel's status as a microkernel.) MkLinux is based on Mach with a
Linux personalitysimilar to the BSD personalitythat OpenStep uses. If you've gotten
the idea that Mach is very flexible, you're right.
Objective C is superior in many ways to C++. It is a true object-oriented language
that functions sort of like a cross between C and Smalltalk. You will find that Java is
more similar to Objective C than it is to C++. The nice thing about Objective C in
relation to OpenStep is that the runtime object server is part of the core OS, so you get
a very high percentage of code reuse.
As an example, I probably have in the neighborhood of 100 instances of the Text class
currently running on the screen of the NeXT cube I am using to type this article. All of
them are using the same piece of code in memory, and only the data for each object
differs. Applications that use common object classes such as Text, Window and Button
can use hardly any memory, because it is possible for them to use very little new code.
OpenStep can be very efficient, and the only development system even remotely
comparable is Smalltalk. In short, OpenStep is a developer's dream - keeping NeXT in
business despite arguably the worst overall smart-but-dumb management in the
computer industry.
Finally, there are some wonderful surprises in store for Macintosh developers. The
first is that NeXT has enhanced OpenStep with some pseudo-realtime capabilities for
developers wanting to do animation. These capabilities take the form of the
DPSTimedEntry, a request to the operating system to call a certain function at a
certain interval. Since OpenStep is a preemptive multitasking system,
DPSTimedEntries are not truly realtime, but the system usually has no trouble
achieving granularity fine enough for seamless animations.
The second surprise is that OpenStep's 3DKit is based on Renderman, the scene
description language from Steve Jobs' other company, Pixar. You may recall
Renderman's scene description language was used to create the movie Toy Story, and
there truly is no substitute. Some of the best modeling software available is built on
OpenStep and 3DKit, and many Mac developers will be ecstatic to gain access to
Renderman. It's built into OpenStep's development libraries.
OpenStep's Weaknesses
One of OpenStep's greatest weaknesses is its unix file system, and the BeOS is far
better than OpenStep in this area. From the point of view of a Mac programmer, the
unix file system might seem great at first because of its reliability, support for
essentially unlimited path- and filename-size, and great support for security.
Unfortunately, however, the unix file system has grown pretty archaic in many ways
and it is arguably unsuitable for a personal computer. Long ago NeXT promised
OpenStep developers that there was a completely revamped object-oriented file system
on the way, similar to the BeOS or Newton OS. It never arrived. Hopefully Apple will
bring it out.
The BeOS also has it all over OpenStep when it comes to device management. BeOS
devices are just as object-oriented as the rest of the system, which means that a BeOS
device isn't actually instantiated until it's needed. It can be linked and unlinked on the
fly, and I have to say I was completely blown away once by the sight of a Be computer
rebooting before its (still-warm) monitor could warm up. The system booted with
only the devices it needed, saving the rest until an app used them.
The last place BeOS is really stellar is in its multiprocessor support. There's no real
excuse for the lack of it in OpenStep; NeXT just never got around to releasing a
threadsafe version of the AppKit (the large library of object classes). So, we have an
OS running on a multiprocessor-capable kernel with multithreading applications but
no multiprocessing because nobody ever got around to revamping the object libraries.
It's a sure bet someone will fix this problem quickly, in fact, NeXT had a version of
NeXTStep running on a multiprocessor machine before they got out of the hardware
business. Some OpenStep people get sort of steamed when you bring up this topic.
The new version of OpenStep, 4.0, is also no longer POSIX-compliant and that broke a
lot of applications. Lots of OpenStep people get pretty steamed about this topic as well.
OpenStep is far less flexible than MacOS when it comes to game or multimedia
development. Something like RAVE+Game Sprockets is needed badly.
Last, but not at all least, the OpenStep Workspace Manager GUI needs a revamp as
much as the Finder's GUI. In some ways it is more friendly, but in some ways it really
needs many of the same changes the Macintosh Finder is getting. Again, not a hard
problem to solve.
Conclusion
That summarizes Apple's acquisition of NeXT Software from the point of view of a
longtime Mac fanatic and OpenStep developer. I still really can't figure out what at
NeXT was worth $400 million, but it's a great PR move and I think it was done right.
I'm happy to have Apple supporting my favorite OS, and I can now postpone my port of
Objective C to the Macintosh yet another time. Like many OpenStep developers, I got a
better Christmas present than I could ever have imagined, and I think everyone who
will use a computer in the next few years did also.