My first contact with Linux occured in 1996. I was in high school and I opened a telnet connection from a DOS box to a RedHat 5.0 server and used lynx to browse the web and pine to read my email. During the next three years (1996-1999), the Internet was an all-Linux all-textmode world for me.
I would be willing to bet that humans could live in 2.5 G. The human body is incredibly resilient, especially when it has grown up in a new environment. There are people living everywhere from sea level to several miles up, and in environments ranging from yearly average temperatures of over 30C to under 0C.
I think so too. That would certainly trigger a quick evolution of the homo sapiens towards another human species better adapted to life on that planet.
Eveb people who live in different environments on Earth exhibit different features that allow them to adapt to their environment.
I imagine that at least in the beginning the people who would colonize a 2.5G planet would become shorter, due to the fact that gravitational pull would make their upper body weight press harder on the ribs and pelvis.