Herobrine is the subject of a community-made creepypasta. He is one of the major community icons of Minecraft, yet Herobrine has not been present in any version of Minecraft.
The first story and image ever posted about Herobrine, as well as the Brocraft stream, are regarded as canonical. Things posted after these two events are considered fan-made adaptations and variations.
Herobrine is not in unmodded Minecraft, and never has been. There are no references to him at all in the source code, and there is no code to allow for any entity to act like Herobrine. It is not possible for Herobrine to have ever existed in any unmodded clients or servers. Any appearances of Herobrine are caused by either mods being installed or because of another player using the skin.