CCP and Hadean managed to make use of Aether Engine to put 14,274 ships into battle against one another, resulting in just over 10,000 concurrent ships in a battle. Naturally, this provided some major casualties and broken records.
CCP and Hadean's stunt happened on the first morning of GDC where 3,852 players joined the battle to help test out Aether engine's capabilities. The battle was later joined by a pile of AI-controlled ships, bringing the total to 14,274 ships during the course of the event.
The concurrent participating ship peak was a bit lower though, standing at 10,412 which was still enough to break through the initial goal which was exactly 10,000 ships in a deathmatch. At the end of the battle, thanks to respawning and the massive numbers, the total casualty count was 88,988 destroyed ships.
While the massive battles sound epic indeed, EVE Online fans shouldn't get too excited just yet as this was just an even to showcase what Aether engine could do. Still, the numbers EVE Online players set earlier are nothing to be ashamed of either, as the game already holds the Guiness World Record for “most concurrent players simultaneously involved in a single multiplayer PvP videogame battle” where to concurrent player count peaked at 6,142 players on 28 January 2019.
It is sadly uknown whether we will actually see something like this happen online in the actual anytime soon as EVE: Aether Wars was just a showcase and EVE Online doesn't use Aether engine. Craig Beddis, Hadean's CEO, hinted at more collaboration in the future, saying that they are "even more excited about the possibilities" of the partnership between the two companies, some of which could be to "push the technological boundaries of what's possible in the MMO space".
Hilmar V. Pétursson, CCP Games’ CEO, shared the sentiment, stating that he believes the partnership will "continue to break new ground" in hopes of making EVE Online a game "that will outlive us all". That's both quite morbid and ambitious, but no one knows what the future has in store for us.