The Sharp Zaurus (SL-5000D) is an ARM-based PDA. It compares, roughly, with the Compaq iPAQ 3650, the HP Jornada, and others, but with one exception: it comes running Linux. Needless to say, this is exciting to millions of Linux users the world over.
Besides running Linux, the Zaurus runs QPE, the Qt Palmtop Environment, and comes with a Java interpreter. QPE provides you with the basic set of palmtop applications that the Palm has accustomed people to having: a calendar, address book, calculator, clock, email, text editor, and todo list.
Since the only other comparable handheld to run Linux is the Compaq iPAQ, it makes sense to compare the two. The iPAQ can run QPE, and in fact the icon for suspending the developer Zaurus is a picture of the iPAQ's power button. Certainly while running QPE, the Zaurus and iPAQ are roughly similar. The iPAQ also runs the Familiar distribution, which uses X, but the Zaurus will soon run Familiar as well.
The best way to compare the two is at the hardware level, since software is malleable but hardware not. The screens are roughly the same size (the Zaurus's is slightly smaller), and are exactly the same resolution, 320x240). The Zaurus can do 16 bits per pixel while the iPAQ is limited to 12 bits per pixel. The backlights are equally brilliant. The Zaurus has a removable translucent screen protector.
The Zaurus has 7 buttons, plus a four-way joypad with center button. The iPAQ has 6 buttons, plus a four-way joypad with center button. One of the iPAQ buttons is dedicated to power at the kernel level. The Zaurus has a mini keyboard which is exposed by sliding down the buttons, which cover the keyboard.
The iPAQ has a microphone, speaker, and headphone jack. The speaker is somewhat tinny owing to its small size. The Zaurus has no microphone, and a piezo speaker; even more tinny. It has a stereo headphone jack which can supposedly be switching under software control into a mono-out, mic-in jack. The iPAQ has no audio-in jack.
Both machines have IrDA ports, USB, and a serial port. 'Nuff said.
The Zaurus comes with a CF slot (Compact Flash) and SD slot (Secure Digital), the former for memory but more useful for I/O, and the latter for memory because of its tiny size. The iPAQ has optional sleeves. The Compaq by itself is slightly thinner (about 1mm) than the Zaurus. With CF sleeve, it is about 5mm thicker. One advantage that the iPAQ has over the Zaurus is that the iPAQ has a PCMCIA sleeve, and dual PCMCIA sleeve. The Zaurus will never have these because there is no way to get access to the necessary signals-- they aren't present on the CF pins.
Which do I like better? It's not obvious. An advantage of the Zaurus over the iPAQ is that it comes with Linux. However, the iPAQ uses the JFFS2 filesystem, which is more advanced than the cramfs filesystem used by the Zaurus. To get those advantages you will have to install your own version of Linux regardless. Plus the iPAQ running X has anti-aliased fonts. They make a huge difference in readability on a small LCD screen.
Certainly having the SD slot and CF slot built-in make the Zaurus more expandable. However the Compaq's slot is not proprietary and they publish the details of how to use it. You can expect third-party sleeves for the iPAQ, which is selling like gangbusters. Indeed, Compaq Research Labs has produced a sleeve for their own research, with an extra 32M flash, accellerometer, dual PCMCIA slots, extra batteries, and camera.
The Zaurus's mini-keyboard is very useful. My mother-in-law claims to be able to touch-type on it. With my fat fingers, I can hunt-n-peck reasonably well. On the other hand, Familiar comes with a full-screen stroke recognizer.
On a minor point, the Zaurus has two lanyard connectors, on top and bottom. Nobody wants to drop a $500 computer. And yet, the iPAQ lacks these connectors even though, with the pcmcia sleeve, the iPAQ is fairly hefty.
Both devices are worthy of attention. If I were writing a Java application, I would pay attention to the Zaurus, with its included Java VM. Same thing for a QPE application, since QPE comes standard. If I were writing an X application, I would pay more attention to the iPAQ, with its X server. If Familiar is ported to the Zaurus, Compaq had better sit up, pay attention, and consider producing a Linux version of the iPAQ, because their main advantage over the Zaurus will be lost.
If I were Sharp, I would position this product directly at the iPAQ market, and woo Linux developers. Fortunately, they seem to be doing just that, with their pre-release developer program.