What just happened? The iconic instant messaging app ICQ, which basically kicked off the whole online chat era, is finally biting the dust after nearly three decades. The software known for its iconic "uh-oh" sound when you receive a message shuts down on June 26.

The shutdown announcement came via a pretty unceremonious update on ICQ's website last Friday – just a simple "ICQ will stop working from June 26" note along with a nudge for users to migrate to the messaging platforms from VK, the Russian social media company that's owned ICQ since acquiring it from AOL way back in 2010. America Online acquired ICQ back in 1998 for $400 million. Those were the days when ICQ's addictive notification sounds and the UINs (User Identification Numbers) we all obsessively memorized were cutting-edge stuff.

As smartphones and mobile-first chat apps like WhatsApp rose to prominence in the late 2000s, ICQ's appeal began waning despite its new owners trying to modernize it with redesigns and added features. Russian parent company VK pulled the ICQ app from mobile stores in 2022 as it shifted focus to its VK Messenger platform.

To its credit, ICQ has proven shockingly resilient over its three-decade run. Most of its biggest 90s-era competitors, like AIM, Yahoo Messenger, and MSN Messenger, have been collecting dust for years. However, ICQ survived by reimagining itself as a desktop messaging app and web service in its twilight years. Its newest releases gave the app a more modern messaging experience with extras like smart replies and video calling – but the refresh wasn't enough to keep it kicking in the fiercely competitive messaging market.

At its peak, ICQ saw over 100 million registered users. That may not sound like a lot compared to the billions of active users today's social platforms boast, but this was way back in 2001. As of 2022, the platform had dwindled to about 11 million monthly users.

Although users should expect service to cease entirely on June 26, this might not be the final time we'll see those three iconic letters. The app's official X account shared a cryptic Terminator "I'll be back" meme on Friday after the shutdown news broke.

While the odds of ICQ ever recapturing its 90s/early 2000s glory days are slim, its demise marks the end of an era as one of the last remnants of the early internet.

So what's your oldest ICQ memory? Do you still remember your UIN? We'd love to hear down in the comments.