Sampo Park Relaxation, or Sapari/SAPARi for short, is a 3D MMO made by Sony in 1997, using the file format VRML (Virtual Reality Modelling Language,
see more Here). In 2001, fees were applied to it and the number of players decreased, until 2003 when the service ended for good. Thanks to the Internet Archive, it can still be downloaded and played! 
The CPB Pack I made
Barra's website
Koko's website