1. Frontier

Frontier is installed at the Oak Ridge National Laboratory (ORNL) in USA's Tennessee. It is built by Hewlett Packard Enterprise.

2. Fugaku

Fugaku is housed at the Riken Center for Computational Science in Japan's Kobe.

3. Lumi

Lumi is being used in Finland and is built by Hewlett Packard Enterprise.

4. Summit

Summit is working at ORNL in Tennessee. It is being used to tackle climate change, predict extreme weather and understand genetic factors.

5. Sierra 

Sierra is currently running at the Lawrence Livermore National Laboratory in California. It is being used to maintain the reliability of nuclear weapons.