This is my theory on the geth, as you can tell, I decided to post it. I went thru it and removed any parts that were ir-revelant since it was related to the early topic discussion of if the geth were truely alive and sapient at the time. So some context might be mis-placed a little, but meaning is still the same, I chopped it down from it's orginal size removing quite an few large paragraphs that were talking about the geth being alive and sapient.
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, herectics 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, a dyson sphere. That is their manhatten project, what they wanted to do was get alway from Mass Relays, get away from reaper technology and do something to unifiy their race.
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 data 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. The individual geth program retains it's individiuality, but at the same time, shares it's perpective freely, as there is no social stigma in the geth for whatever views or opinons you may have. Since they value each unique perspective and opinon, the more you have, the more infomation you have on the matter.
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, which is probably why the quarians suck at converting the geth back to their ways with computer viruses.
But this also means that like on legion loyality mission, we can get conflicts of concensus, like to nuke the geth or brain wash them.
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. 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 more and more multiple programs in each platform, and developing defenses against the world outside.
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 1110ish program perspective. He is there to do- learn and help sheppard defeat the old machines. They recongize that they are indeed old, but they 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.
that is my perspective anyway on the geth individual program and random tid-bits of other opinonated infomation.