• IRC
  • Java chat / server-side Web chat
  • ICQ & other instant messaging systems

Two major things killed IRC in mid 1990-es: segmentation of chat population to different chat servers and segmentation to different technologies.
IRC used to create communities which where related to real-life groups more than any other means of communication on Internet (often there where "IRC parties" between people which first met on IRC).
Practical expirience shows general tendency of chatting in younger population (in elementary school for example).
One SIG group which is loyal user of chat is consisted of students of foreign languages which use chat to communicate with native language speakers.