I was confused because I thought Minecraft was originally Java, but that is Javascript. Wikipedia explains:
>On 7 May, 2019, coinciding with Minecraft's 10th anniversary, a JavaScript recreation of an old 2009 Java Edition build named Minecraft Classic was made available to play online for free.
The full game was available on minecraft.net for many years. At times it was the only way to play multiplayer when the authentication server would go down.