I was beginning to write the net code for a game me and a few others are working on. I was planning on using C sockets, I have a bit of experience. It seems to me that writing the code to actually send the packets isn't that difficult. On the other hand, programming the system to know how to use the data that you receive is where the challenge is. My question is, what is it that Net Code Libraries do that make them so helpful? Do they automatically format the packets for you such as if I wanted to send "Hello", it sends 05Hello and all you have to worry about is that you got "Hello" on both sides? Or do they provide some sort of support that is extremely helpful for game programming? Does it just provide a way to send data without worrying about handling reads and writes?

Well, I haven't tried another libraries, but I've done one. You only need to use a function to add an opcode (you tell the opcode number, and a function that will be called when it arrives). For example...

#define OP_TEST 0
void test(char* data,int32 size){
printf("Hey, %s arrived!",data);
}
void main(){
CofruNet* CN=new CofruNet(1); //1 opcode
CN->AddOpcode(OP_TEST,test);
CN->StartClient(someip,someport);
CN->StartReceive();
while(1){}
}

This is a client example, sure it containts functions for server. So when a packet of opcode OP_TEST arrives, it will decompress it(if compressed bool was true in the CN->Send function) and call the function 'test' with the data and size. It is really easy to use, most things are automatic. If you wanna test it, download the library from http://cofruben.krusher.org