Goodbye, IBM. Seriously.

For those of us who worked at Apple in earlier days, the company's current success is sometimes surreal.  I had one of those moments today.  Back in the mid 1990s, we were struggling to get to $10 billion in revenue per year, a figure that seemed ridiculously high.  This week, Apple reported quarterly revenue of $27 billion.  Apple is almost certainly now a $100 billion a year company.

To put that in perspective, Apple is now larger than companies like Honda, Sony, Deutsche Telekom, Procter & Gamble, Vodafone -- and IBM.  Apple is very close to passing Samsung and HP, which would make it the world's largest computing company.

In 1981, when IBM entered the PC business, Apple ran a big ad in the Wall Street Journal saying "Welcome, IBM. Seriously."  At the time, everyone thought it was a very cheeky move by a tiny upstart company.  No one -- and I mean absolutely no one -- would have believed that 30 years later Apple would be looking at IBM in the rear view mirror.

The spookiest thing is that Apple may still have a lot of room to grow in both mobile phones and tablets.  There's no way the company can keep growing like this indefinitely, but it's very hard to predict exactly when it'll slow down.