Artemis is designed for anyone who watched Star Trek and dreamed of what it would be like to sit on the bridge of a star ship. Artemis simulates a spaceship bridge by networking several computers together. You cannot play Artemis single-player!
Most popular community and official game content for the past week.  (?)
What does popular mean?
It means the content you're seeing has been rated up more than it has been rated down for the given time period.