Downloading OptiFine for older versions of Minecraft ("tutorial")

As some of you may know, OptiFine's official website only goes as far as 1.7.2, even though the mod itself is far older than that. Luckily, there is an archive which encompasses versions from beta 1.4 to release 1.8.9: https://www.minecraftforum.net/forums/mapping-and-modding-java-edition/minecraft-mods/1286605-b1-4-1-9-optifine-history. The problem is that the links are completely dead.

The simple fix is to click on "mirror", then change "optifined.net" to optifine.net" in the URL. This should work for all of the versions, although I haven't tested every single one.

As for why they're not listed on optifine.net, I have no idea. My best guess is that they contain some of the Minecraft code, so they may be violating copyright or something along those lines.