GOOD QUESTION!!
SAPARi, (さぱり) was a "Community Place" 3D chatroom developed by Sony in 1997 and was preinstalled on Sony's VAIO laptops between the late 90's to early 2000's where its popularity peaked. Due to server fees, SAPARi was switched to So-Net where it then became a paid service in 2001. Immediately afterwards, SAPARi died in popularity and was later shut down in 2003.
did you know? Sapari has 101 Avatars!
SAPARi had a sudden resurgence in late 2020 in a Osamu Sato discord server where SAPARi was rediscovered. A discord server was later made where a netcode reverse engineering effort was done. Sapari now has joinable servers which you can access through the Discord server. (Linked below)