It’s a sad day.

Steven P. Jobs, the Apple Inc. chairman and co-founder who pioneered the personal computer industry and changed the way people think about technology, died Wednesday at the age of 56.

His family, in a statement released by Apple, said Mr. Jobs “died peacefully today surrounded by his family…We know many of you will mourn with us, and we ask that you respect our privacy during our time of grief.”

The company didn’t specify the cause of his death. Mr. Jobs had battled pancreatic cancer and several years ago received a liver transplant. In August, Mr. Jobs stepped down as CEO, handing the reins to Tim Cook.

“Apple has lost a visionary and creative genius, and the world has lost an amazing human being,” Mr. Cook said in a letter to employees. “We will honor his memory by dedicating ourselves to continuing the work he loved so much.”

I grew up using Apple computers, had to switch to PC for college (architecture’s industry standard CAD software AutoCAD was PC only then) and switch back to Mac after graduation. I own various incarnations of iPods. I use my iPhone like my life depends on it. I will get the next iPad. Last year I started running with the encouragement of software that would not exist had it not been for his vision.

Jobs was a man of genius and vision. May he rest in peace.