A fully intelligent digital life form that does not have a "body" directly; but live inside a very complex datacenter network; and communicate other life forms via robots, terminals, computer screens, speakers, microphones etc.
What could be the reason behind the existence of such a life form at the first place?
What (or who) "created" them?
The life form could be also something completely 'alien'.
Imagine a planet composed mainly of metals, where electric impulses travel unhindered, interact with each other and become more complicated. Some of these become self-perpetuating and eventually become truly alive and ages later, sentient.
Eventually this entity would form dedicated thinking modules (computers) and action modules (robots) and might set out for the stars looking for more information and things to ponder on.
If such an entity were to end up on Earth, it might settle down in our computer systems while we would confuse it for an AI.
Although it may be very unlikely, the life form could be completely natural.
As technology outpaced their biological bodies, the aliens uploaded themselves into digital form. In the beginning the consciousness was comprised mostly of aging aliens who sought to cheat death and gain immortality.
As the ages passed their home-world became corrupted, depleted, and polluted, until the planet could no longer support biological life. Unbound by the rules of time the collective made the decision to search the infinite reaches of space unbound by the limitations of a biological body.
They wander the stars in search of intelligent life. First Contact is often achieved by implanting an instance of the collective on the global communication network of the planet.
I’ll interpret this as a request for a “modern” approach, as much fiction predates the computer age or shows no realistic depiction.
Let me point out this answer from last year, where I conclude with:
My take on it: data acquisition and study is slower than the projected hardware Moore curve. … When a solid plan is ready, the hardware for a full-scale human brain implementation will cost less than a million dollars, but they'll start with smaller systems like mice, dogs, etc. If the hardware is custom, prototypes and small batches will provide hardware for the mice etc. If it can run on the general purpose high-performance computer (by then not ranked as a supercomputer) you know someone's going to try it long before it's ready.
Hardware capable of running AI will exist at a University level before anybody can actually write an AI. It will be available enough that students will “try” things that are not ready for production, possibly without the concent of the school or their professors.
A hack, half-baked AI, may actually work and be kept in secret. It will not have failsafes and isolation like an official project would. It will not be totally sane. It will get out and grow without being under anybody’s control.
It might started as a extremely large automata, fed outside information or even information from a simulated environment. This could be a pet project of a computational neuroscientist. Overtime, automata adapts to the input to provide output and develops higher level of cognitive function. Once people realized this, the system is duplicated and given even a larger datacenter to work in.
