Let's say you wanted to change the limit of total bitcoins

[ewarrior]

As I understand any changes are not possible because there is no centrally controlled software.

So If you want to change any fundamental rules you would have to release bitcoin v2? and start from scratch?

[ruski]

The client is centrally controlled. They could extend it with the next release if they wanted. Everyone would have to use the new client though.

[ewarrior]

Are you sure? I thought that the client is only an interface. All the actual "meat" is not changeable. Since the code is not centrally controlled.

[riX]

There are more than one client, pick one or make your own with custom rules.
If you change the limit of total bitcoins in your client, and also includes mining software, you would effectively create a fork of the blockchain.

[bitcon]

i think he's talking about the total number of bitcoins that will ever be produced by the network.  21million i believe.

[ttk2]

The client is centrally controlled. They could extend it with the next release if they wanted. Everyone would have to use the new client though.

No, they could not, the total number of generated coins is based on the formula that governs block generation, as such any change to this formula would require the creation of a new genesis block and it would invalidate all old blocks. Essentially starting the Bitcoin network again from scratch, you could not transfer Bitcoins between the network with the old formula and the network with the new one. This is a core function of Bitcoins, no matter what you can not make more than 21 million without starting a new network. 

[Weaver]

Hypothetically you could make a client that interprets .1 btc as 1 bitcoin... and multiply the network that way... totally worthless... but makes there be more volume... sort of.

[elements]

"Let's say you wanted to change the limit of total bitcoins"

Let's not!

[bitrain]

 Everything is perfects as it is . Final number of bitcoins doesn't mean anything.