Ahn Cheol-Soo: Software tycoon, political novice
AHN CHEOL-Soo has known many incarnations - doctor, software mogul, college professor - but none that obviously pointed to a future run at the South Korean presidency.
But over the past four years, the soft-spoken 50-year-old has built a large if unorganised political following by addressing issues often sidelined by South Korea's rapid economic growth.
"We need to root out widespread and illegal practises by big conglomerates," he said in a recent interview, accusing them of using their commercial and political clout to smother start-ups that might threaten their business.
"Even if smaller firms complain, authorities only review a tiny fraction of such complaints, eventually in protection of bigger firms," he complained.
His comments resonated with younger liberal voters, who see Ahn as a figure untainted by corruption and political or commercial abuse of power.
That popularity saw him courted by politicians across the political spectrum, but he has remained without party affiliation despite an obvious empathy with the liberal opposition.
His image was further boosted a month later when he promised to donate 150 billion won (RM409 million) worth of shares in his AhnLab software firm to charity.
Ahn has repeatedly admitted that his somewhat nerdy, reserved personality is a poor fit for the cut-throat world of South Korean politics and others have agreed.
"If Ahn wants to become president, he should get rid of his goody-goody image first ... a president who wants to be nice all the time can hardly manage the country," conservative Dong-A Ilbo daily said in a recent editorial.
Born in 1962 in the southern port city of Busan, Ahn earned his medical degree at Seoul National University (SNU).
He became the youngest-ever head of a medical college in Dankook University at the age of 27, but quit the prized job to found AhnLab in 1995.
The firm thrived after the CIH virus in 1999 caused widespread damages in countries including the South, fanning demand for anti-virus software.
He resigned as CEO in 2005 to study business at the University of Pennsylvania, while remaining as AhnLab board chairman.
After returning from the United States in 2008, he taught at Korea Advanced Institute of Science and Technology, the nation's top science school, before becoming dean of the SNU's School of Convergence Science and Technology in 2011.