The Model 3107 Chair–known more often by its official nickname, the Series 7–might very well be the most popular designer chair in the world. Inspired by Charles & Ray Eames’ work with moulded plywood, over 55 million units have been produced since Arne Jacobsen designed the first Series 7 was produced in 1955. It’s also believed by many to be the most widely copied chair design in the world.

It seems appropriate, then, that to celebrate the 60th anniversary of their iconic chair, Danish furniture brand Fritz Hansen commissioned seven architects to make copies of the Series 7 in the likeness of their own signature styles. The project is called 7 Cool Architects, and the “cool architects” in question are Bjarke Ingels, Carlos Ott and Carlos Ponce de León, Jean Nouvel Design, Jun Igarashi, Neri & Hu, Snøhetta and Zaha Hadid Design.

Although all of the designs in question stay true to the graceful, sinuously curving form of the Series 7, they all reimagine it in various ways.

Zaha Hadid’s bright green interpretation replaces the legs of the chair with a tripod of steel loops, which “sweep down to the ground and reach up to embrace the undulating shape of the iconic plywood seat.”

Bjarke Ingels, on the other hand, turned the Series 7 into a sculpture by taking a dozen odd Series 7 shells and stacking them with springs in between, creating a kind of Series 7 slinky.

Snøhetta, meanwhile, took the shell of a Series 7 and made it the centerpiece of a small garden. “Since we set the chair free, we felt that the chair could be used for a large number of our projects,” they said. “We try to maintain a good link to the outdoors throughout all our work and that’s why an outdoor chair is perfect for our projects.”

Jean Nouvel Design joined two Series 7 chairs together, facing in opposite directions, and reinterpreted them as the Chinese yin-yang.