To demonstrate Moore's Law
Take a piece of paper, divide it in two, and write this year's date in one half:
Now divide the other half in two vertically, and write the date 18 months ago in one half:
Now divide the remaining space in half, and write the date 18 months earlier (or in other words 3 years ago) in one half:
Repeat until your pen is thicker than the space you have to divide in two:
This demonstrates that your current computer is more powerful than all other computers you have had put together (and the original Macintosh (1984) had tiny amounts of computing power available.)
Mostly for pixel pushing.
Most computers spend most of their active life idle.
Why aren't we using the extra power to make people's (our!) lives better?
According to the DoD, 90% of the cost of software is debugging.
According to Fred Brookes, in his classic book The Mythical Man Month, the number of bugs increases quadratically according to code size: L1.5.
In other words, a program that is 10 times longer is 32 times harder to write.
Or put another way: a program that is 10 times smaller needs only 3% of the effort.
Recent interest generated by Google Maps and GMail. One of the big advantages is that everyone has always got the most recent version. Hard to write though: Google maps is more than 200k of code.
The problem is, no one writes applications except programmers.
Interesting exception: spreadsheets
Mostly because they use a declarative programming model.
The nice part about declarative programming is that the computer takes care of all the boring fiddly detail.
Some of the most interesting work in this area is being done by xport.net with their Sidewinder browser.
What they have done is combined XHTML, XForms, SVG and XBL. The SVG is essentially a stylesheet for XHTML+XForms content, being applied using XBL. For instance:
The code says:
<xf:output value="..." appearance="fp:analogue-clock" class="clock">
The output is then something like 11:30:00, and the SVG turns this into an analogue clock (the XBL keys off the 'appearance' attribute).
Remember, empirically, a program that is an order of magnitude smaller needs only 3% of the effort to build.
The advantages of this approach are: