Purely server-side tech is less sensitive to this kind of swing because you control the execution environment. Likewise for open-source software, and software b

Purely server-side tech is less sensitive to this kind of swing because you control the execution environment. Likewise for open-source software, and software based on open, widely used technologies, protocols and specifications - for example, it's unlikely that HTTP is going away in the time it takes for a startup to outgrow its "startup" status. All of this applies to PHP, so I can't see it being killed off anytime soon, regardless of technical merit. (I wouldn't choose it for a bunch of other reasons, but those are subjective)