EL SEGUNDO, California - She is turning 60 this year and it's still a Barbie world.

Blonde or brunette, slender or curvy, black or white, princess or president, a Barbie doll is a forever favorite for young girls, even if she has caused controversy over the years.

The iconic doll has evolved to keep up with the times - check out her Twitter feed.

And despite fierce competition in the toy industry, 58 million Barbies are sold each year in more than 150 countries.

"In an industry where success today is three to five years, 60 years is a huge deal!" said Nathan Baynard, director of global brand marketing for Barbie.

Around the world, Barbie is as universally known as Coca-Cola or McDonald's, Baynard said during a recent visit to Mattel's design studio in El Segundo, a suburb of Los Angeles.

In all, more than 1 billion Barbie dolls have been sold since she made her debut on March 9, 1959.

She was invented by Ruth Handler, the co-founder of Mattel, who was inspired by her own children to create the doll.

"Her daughter Barbara was limited in the choices of her toys - the only ones were baby dolls," Baynard recounted.

Barbie is, of course, a shortened version of Barbara.

The doll was supposed to teach girls "that they had choices, that they could be anything. In 1959, it was a radical idea!" Baynard said.

Barbie was an instant success. In the first year, 300,000 dolls were sold, he added.

From the start, however, Barbie's pinup measurements didn't immediately seem all that feminist, and would spark criticism for decades to come.

"In 1959, her body structure was exaggerated to match the aesthetics of the time and the fabric available," said Barbie designer Carlyle Nuera.

Since then, Mattel has made many changes - introducing multiple body types and dozens of skin tones.

In 1965, four years before Neil Armstrong walked on the moon, Barbie became an astronaut. In 1968, the first black Barbie doll hit store shelves.

Lisa McKnight, senior vice--president and global general manager for the Barbie brand, said 55 percent of the dolls sold around the world have neither blonde hair nor blue eyes.

Mattel has more than 100 people working in the El Segundo design studio, a massive hangar-like building wedged between Los Angeles International Airport and a freeway.

"Sometimes, you see her on a shelf and then it gets back to you: oh yes, I designed this one!" Nuera said.

Agence France-Presse