Steve Jobs has written to Apple’s board of directors:

I have always said if there ever came a day when I could no longer meet my duties and expectations as Apple’s CEO, I would be the first to let you know. Unfortunately, that day has come.

I hereby resign as CEO of Apple. I would like to serve, if the Board sees fit, as Chairman of the Board, director and Apple employee.

As far as my successor goes, I strongly recommend that we execute our succession plan and name Tim Cook as CEO of Apple.

I believe Apple’s brightest and most innovative days are ahead of it. And I look forward to watching and contributing to its success in a new role.

Apple is at times an infuriating company, but it is infused with genius that Jobs has inspired and nurtured.

I do not know how the computing landscape today would look without his influence, but I am convinced that it would be very different and largely worse.

Under Jobs, Apple refined personal computing with successive versions of the Mac, reinvented the music industry with iPod and iTunes, made the first mobile phone that was a delight to use and freed us from the tyranny of mobile operators so that the promise of the mobile internet could be fulfilled, and created the first tablet computer that is sufficiently useable and affordable to bring touch computing to the mainstream.

I count that as four milestones, any one of which would be enough to make Apple a great company. Most companies live forever on their first and only breakthrough idea or technology; only Apple has continued reinventing itself.

Apple inspires devotion from its users not only because of its delightful products, but also because Jobs has fought on our behalf as users, rejecting who-knows-how-many ideas and features that were not quite there and would have spoilt our experience. These are the ideas that most companies deliver as version 1.0 of their product.

Jobs remains at Apple, but his letter suggests that his health is failing so my guess is that his role will be greatly reduced.

Apple after Jobs will be a different company and is unlikely to be a better one, though its strong culture and many brilliant engineers and designers remain. New CEO Tim Cook has been acting CEO for some time so the transition will be smooth.

Thank you to Steve Jobs for making computing better.