VoIP and instant messaging

Instant messaging has been around for almost a decade, as users of then-popular instant messaging clients ICQ and AOL (now considered dinosaurs) can attest—or even more, perhaps in some forms not well-known to the Internet-using public. Voice-over-Internet Protocol, however has seen a rise to popularity in only the recent couple of years. But users may not be aware that even before the popularity of VoIP as we know it, instant messaging and chat clients had been offering working, albeit crude, voice-chatting systems?
I remember that Yahoo messenger and ICQ were among the early adopters of voice chatting. There was no good compression mechanism back then, and residential broadband connections were unheard-of. Hence, what we got were very choppy voice recordings which we had to literally wait half a minute or more for. What’s worse, one had to press an onscreen “push to talk” button before speaking into the microphone. The system was half-duplex, meaning you and your correspondent had to take turns in speaking.
All that for a free call over the Internet!
The world sure has changed with IM and VoIP. Todays more popular IM clients have built-in support for VoIP, although limited to their respective networks. Yahoo messenger, Skype and Google talk have adequate VoIP systems, with Yahoo and Skype even supporting video as a built-in feature. We now take for granted the fact that we can call friends and family on the other side of the world for free, when it was only a decade ago when people were having a hard time trying to experiment with sending multimedia over the Internet.