To throw something into the debate, that is semi related, there was another topic of discussion discussing how the geth operate and if they are sapient, very similar. Here is the argument I presented there, trimmed it down here and there to make it have context to the currently argument.
The Geth are sapient and alive in my opinon, why? Because they are trying to understand the things around them, they listen to the extra-net on an variety of things, trying to understand why organics do what they do. They have the curiousity of humans, brains of an salarian, can form an might military front like the turians and can be just as diplomatic as the Asari are as we have seen in the game.
Simulating Life? Not quite so. I don't really believe it's simulation of life, but then again, are we just simply simulating life? once you remove our sensors, we are much like the geth are we not? just an collection of brain cells talking to each other, wondering why the hell it's dark in here, we can't feel or smell anything. We would be just like the geth, millions of simulating programs that work together to form one concious. In reality, the geth are groups of people at this point, the main collective, and legion. Legion is seperate because he was built to operate seperately from the geth, even when he can not return to the geth... LAN so to speak, he can operate on his own.
Another analogy would be to put legion as the best and brightest that the geth had to offer. Legion could be considered an proto-type of the new geth. And the geth are obiviously building something that will ensure the surivival of their race, hinted at being an dyson sphere. That is their manhatten project I believe.
As we have seen, the geth can modify and build much like we do, have unique perspectives since they can share all their perspectives, however the programs are indeed individual. To be honest, I envy the geth, since they can argue, bicker over an decision for 30 seconds, come back with an census and the decision has been made, while we take days upon days just to form an concensus. I don't believe the geth are just a computer program because what I get from legion is that an individual program may share it's perspective, but it's not uploaded into another program and just accepted, the program that accepts the upload more than likely retains it's individuality.
My best guess is that the individual programs are much like multiple partitions on an computer harddrive.
You have Drive letter C: where you keep your main functions - heart, brain, blood pumping etc.
Then you have drive letter D: this is where you think all the time, where you install all your programs etc etc. This is where you keep your Ideals, Beliefs etc.
You have drive letter E: Where you sample data, choosing to incorporate it into your drive letter D partition or not.
Because untill you accept the program and transfer it over to drive letter D, you have not truely accepted it. Much like a person agreeing with something in one case, but is still conflicted, keeps it to himself.
Because of this multiple drive parition analogy we have, it would mean the geth individual programs operate much like we do, as our brains are divided into "seperate" partitions that do certain functions, like art, math, and then the basic instinict function - the brain stem. This is also how we don't go all art or math and leave everything else behind, it's like an buffer to make sure you don't accept any viruses, or bad ideas at once, which is probably why the quarians are sucking at converting the geth back to their ways with computer viruses.
Now another reason why I believe it is like this is because legion said that an program could be in the miniority with it's decision, but it could ask other programs and see if they accept and gain momuntem that way. If true democracy had an name, it would be the geth collective. My guess is that Soverign inplanted one geth with what he wanted and had that program go back to geth collective - then start to sprout it's ideas, and slowly turn some of the population of the geth into accepting this idea. Much like an prophet coming back and starting an reilgion.
My guess is that the computer virus the herectics had made was something the geth really feared - it was an convicing arguement to join the reapers designed specifically for the geth. It would basically shoe-horn them into accepting the reapers as the only alternative to surivival. When your trying to convince someone to join you, you give analogies, or remind them of something that is important to them etc. You don't go to an farmer and complain about grocery prices, unless you want to talk about the quality of the food that was grown. You give the farmer an arguement he can relate to easily, and you want him to do X instead of Y.
Now, your probably wondering why I am going after the individual programs. Because this is an individual program that has different beliefs, qualms, perspective then the other geth programs around it. Each program is easily unquie by now. Some Geth programs might be better builders, or some might have developed better analgorims for handingly an sinper rifle easier then most geth. Much like the cells in your brain are each unique in their composition, positioning, and how many connectors to other neurons it has. While one can judge an entire society, you can not judge it accurately, without taking it apart and seeing the people underneath.
The Geth are an sophiscated society - they been growing and expanding rapidly for 300 years, and are full of curious programs. To be honest, I see the geth more human like then anything else. They are basically humans from the early ages wandering around the world trying to understand everything even our history are the same which I will present an arguement for and my thinking on the events. Then they got beaten by an stick and realized that they defend themselves, and isolated themselves from the hurtful galaxy that they didn't understand. Even FTL speeds or discussion doesn't give you insight when the only opinon you have is your own. So the geth began development, learning how to incorporate multiple programs in each platform, and developing defenses against the world outside.
They were very right so, the quarians attempted many attacks on them after the initial morning war. They learned of humans years later during the human-turian war and discover that our language is easy to replicate. They begin development on the platform to allow human speech. It was their Oppunity that they could not pass up. A new Kid on the Block. One the geth could ally themselves with. The humans had experinced an similiar surprise war in the begining with the turians. The geth concluded that perhaps this spieces would be willingly to share with them their unique perspectives and give insights to organics considering like the geth.. Perhaps to the point of allying themselves with the geth. The humans recovered and begin to spread to more seperate colonies, no data being avaiable, the geth more than likely thought we would isolate ourselves like they did.
But since they had proceeded with this as plan as an concensus- they went forward with it anyway, adapting the plan since there was still time, 50 years is not an very long time to adapt, unlike the council races with hundreds of years of the same belief and the same rut. But who you do meet with an encounter like this? Who do you send? More than one geth might mean hostility. One single platform was choosen. Who do we send? we would need programs that have been on the extra-net, developing the langauge analgoithms to speak to humans. We would also need repair programs, weapons programs, general knowledge programs, programs that know infomation about the quarians and other council races. They assumed the worse that this platform would be going outside the geth collective, outside their LAN capabilties. So they made the platform self-sufficient with the best and brightest minds the geth could have and send them out on their merry way.
Stargate Atlantis, the first episode is an good analogy for what I mean.
The target - the second potienal human spectre. Someone with enough authority and apparently background who might be willing to ally themselves with Legion. Why not Anderson you may ask? well, legion wasn't ready yet. Legion was deployed after Soverign was destroyed - fully finished. I am guessing that the geth did not deploy him while the herectics were fighting due to the fact that more than likely, sheppard would shoot them. It attempted to follow sheppard but sheppard was killed in action.
Fast forward 2 years and Suddenly the Extranet is crawling with messages about sheppards return. The mission that failed, suddenly was achievable. Legion was hiding, learning what he could from the extranet and watching the council races in their day to day activities while keeping an low profile. Another possbility is that he simply returned to the geth collective and then the same programs were sent out again when sheppard re-surfaced. Legion finally has the perfect oppunity to prove the geth are not all alike, when the reaper IFF is found. He also recieved another mission from the geth collective - obtain technology to combat the old machines, which would be likely coming soon. By killing the husks and immediately saying "sheppard commander." Then turns and leaves. Why do this? It's becuase they know humans are as curious as we are, and want to know why a geth just saved their life, and spoke to them. Geth using our own curiousity against us. so we proceed into the engine core where the geth used the platform to jump down and unlock the door, getting knocked out in the process. I am not totally sure if this was done on purpose, or legion just had bad timing of unlocking the door. My money right now is on purpose because of this reason -. The husk probably did little damage to it, but the geth did something interesting, they turned themselves off. Forcing Sheppard to abide by his/her curiousity and bring the geth onboard. Contact has been made.
A perfect song for the geth in this would probably be "What's This?" - From Nightmare on Christmas. Throughout the game we see legion asking questions about STD's, drugs, drinks, why people do this or that. Making random observations from their 1083 program perspective. He is there to- learn and help sheppard defeat the old machines. They recongize that they are indeed old, but hey call them machines. Machines is an genertic termnology, meaning something that can be applied to both humans and geth alike, including the reapers. The reapers are much like geth I suspect, except that they have gone the path of the herectics and because of that, perhaps instead of being just an mad prophet - have gone to godhood. Much like a mad prophet thinks he is the will of the gods. The reapers, humans, and geth could all be considered machines.
Why? A machine is that does a task, A computer is a machine, yet it can do work that humans could. A human is an bio-machine. We are simply made of different materials. One could be created by another- it's just as easy, because in most reilgions, someone created us. So reason stands if someone else can create us, then it perfectly legitmate that we can make another sapient spieces. Of course this reilient upon the fact that we discover an way to do this, which i am sure if there is an will to do it, there is an way.
In our culture we have seen many different ways of protraying creating an machine race. Either we end up fighting each other or there is an status quo that is formed to maintain co-existence. The Geth want peace with the creators so that is why the homeworld is untouched. They antipciate eventually, the quarians will want their homeworld back, so the geth have built space stations and are guarding it. So in the end, this is why I consider the geth to be legitmately "alive" and "Sapient."
Now this is my arguement on the geth, i admit, It's mostly theory and inference on seavral things. Thought I should throw this into the fray as my opinon.