Steve Jobs is 54 today, but for many in the technology industry, his future at Apple is, sadly, still unclear. Today it emerged that Jobs will not be attending Apple's annual shareholder meeting this week and, once again, we wish him well.

The co-founder and CEO of Apple was born on February 24 1955. As well as his position at Apple, he was also a co-founder of Pixar Animation Studios and is now the largest individual shareholder of Disney.

Jobs stepped down from day-to-day running of Apple last month, citing continuing stomach-related health problems that were "more complex than I originally thought", The CEO has decided to take a medical leave of absence until June, leaving Tim Cook at the helm.

The news broke overnight that he won't be at Apple's annual general meeting, either. This isn't surprising - anybody who has watched Jobs for years will attest how gaunt he looked last year.

However, concerns for Jobs' privacy probably won't abate questions from shareholders, who are concerned at the longer terms effects of the uncertainty surrounding Apple.

After all, the original announcement that Jobs wouldn't be at Macworld was just assumed to be connected to Apple's generally dismissive attitude towards the event; Apple said it wouldn't attend Macworld again.

When he stepped back from day-to-day duties, he pointed fingers at the general all slightly to blame as well, with Jobs noting, "The curiosity over my personal health continues to be a distraction not only for me and my family, but everyone else at Apple as well."

Jobs did say he would keep an eye on things, though as Jack Schofield of The Guardian blogged about on Sunday, it's been suggested that he hasn't logged onto his messaging app since last month. At the time he said "as CEO, I plan to remain involved in major strategic decisions while I am out. Our board of directors fully supports this plan."

Jobs signed off by saying: "I look forward to seeing all of you this summer."

Cook in charge

For now, Tim Cook is at the Apple helm. The former Compaq and IBM executive joined Apple in 1998 with the job of sorting out Apple's manufacturing and distribution.

Cook is one of the safest pairs of hands at Apple, and made some some exceptionally smart deals that made Apple's competitors weep, such as pre-ordering enough flash memory in 2005 to corner the market for at least five years, and he's the man who hammers out iPhone deals with phone companies.

Outside Apple, Cook is on the board of Nike, munches energy bars, is a huge fan of Lance Armstrong and spends most of his free time hiking, biking or in the gym. After his own health scare in 1996 - he was wrongly diagnosed with Multiple Sclerosis - he began competing in cycling events to raise money for MS, and apparently gives away most of his money. He also funds a scholarship at Auburn University, where he did his engineering degree.