Who controls the Bitcoin software?

[Slark]

Bitcoin is in theory community controlled, but in realty is controlled by the tiny development group that decides when to roll out an update.

And the other larger (but perhaps still tiny) community that bothers to see what an update does before they choose to install it.

Don't kid yourself. You as individual have a small or maybe non existent influence on bitcoin. If you are maybe part of development team or close to them you can change something. But as it is now you can only really pick what wallet you will use. That is all.

[DannyHamilton]

Don't kid yourself. You as individual have a small or maybe non existent influence on bitcoin. If you are maybe part of development team or close to them you can change something. But as it is now you can only really pick what wallet you will use. That is all.

You are mistaken.

If a development team tries to change the protocol in a way that I disagree with, then myself and may others will all refuse to use the new protocol.  If enough of us refuse, then the new protocol will just be another altcoin.

If I have an idea that I think would be very beneficial to bitcoin, and the "development team" refuses to implement it, I can program it into the protocol myself and then work to convince others that my protocol is better than the one that is being put out by the "development team".  If I can convince the vast majority of users that my protocol is better, then my software will be the new bitcoin and the old bitcoin will die off.

[minerpumpkin]

The miners add new blocks to the block chain, so unless we change that paradigm, all that full nodes can do is withhold transactions or modify them in some way. That's it.

Perhaps you should try reading the original bitcoin whitepaper so you get a better understanding of how bitcoin works before you try to explain it to others?

The full nodes decide whether a block is valid.  If it doesn't conform to the protocol rules that the full node enforces, then it isn't added to the blockchain.  Then if some other miner creates a block that does conform to the protocol rules, the second miner will be awarded the block reward and will get their block added to the blockchain, while the first miner will see his block ignored by the entire bitcoin userbase.

If the miners that try to change the protocol can convince ALL users to use their new protocol, then their block will get to be added to the blockchain, and the miner that is using the old protocol will see his block ignored and unused.

If only some of the users switch to the new protocol, then the blockchain will split.  A new altcoin will form that uses the new protocol.  The miners that are trying to change the protocol could try and call their altcoin "bitcoin" if they wanted to, but it would be a new-bitcoin.  Meanwhile any miners and users that continue to use the original protocol will still be on the old-bitcoin and will ignore any blocks from the new system.

At that point there are a few possibilities.

It is possible that either the old-bitcoin or new-bitcoin protocol eventually wins out and nearly everybody switches to one protocol or the other.  From then on that protocol will be recognized by the general public as the "real" bitcoin and the other will be some niche system used by fanatics that  the rest of the world ignores.

It is possible that both protocols gain enough support and mining power to remain secure and from then on there are two separate bitcoin systems (bitcoin-1 and bitcoin-2).  When trying to spend your bitcoin, you'll have to make sure that you have coins on the correct network based on what the merchant is willing to accept.  It'd be a bit like choosing between Visa and Mastercard.

It is possible that uncertainty and lack of consensus would destroy the faith in both systems, resulting in a total destruction of value.  Everyone might abandon both bitcoin systems and switch to an entirely different crypto-currency or abandon the concept of a cryptocurrency entirely.

There may be a few other possibilities, but those are the three that first come to mind.

Your technical explanations and implications for the future of Bitcoin are all true and valid, but it is effectively the miners' decision which rules are enacted. If 75% of the full nodes decide to adhere to a different protocol (some other rules that aren't allowed now, whatever) the Blockchain that's being mined will still adhere to the old rules. Nothing has changed.
Now if miners decide to adhere to that protocol, they effectively create a fork - which fork survives or if both continue to exist is another story.

[DannyHamilton]

Your technical explanations and implications for the future of Bitcoin are all true and valid, but it is effectively the miners' decision which rules are enacted. If 75% of the full nodes decide to adhere to a different protocol (some other rules that aren't allowed now, whatever) the Blockchain that's being mined will still adhere to the old rules. Nothing has changed.
Now if miners decide to adhere to that protocol, they effectively create a fork - which fork survives or if both continue to exist is another story.

If 75% of the full nodes decide to adhere to a different protocol, I guarantee you that at least one miner will adhere to the new protocol.  Miners will mine the coins that bring them a profit.  With only 25% of the full nodes accepting, relaying, and broadcasting transactions on the old protocol there will be miners that will switch to the new one.

Therefore, there will be a fork.

[BurtW]

Your technical explanations and implications for the future of Bitcoin are all true and valid, but it is effectively the miners' decision which rules are enacted. If 75% of the full nodes decide to adhere to a different protocol (some other rules that aren't allowed now, whatever) the Blockchain that's being mined will still adhere to the old rules. Nothing has changed.
Now if miners decide to adhere to that protocol, they effectively create a fork - which fork survives or if both continue to exist is another story.

Evidently you did not grasp the concept that if only the miners change the rules but none of the nodes change with them then the incompatible blocks produced by the rouge miners will all be dropped by all the nodes in the system.

All of those dropped blocks will go nowhere - making the rouge miners no money, while at the same time the unchanged miners get the benefit of the lowered hash rate due to the rogue miners flushing all their hashes down the toilet.

So, the miners will not do that.  They will only change if at least some, preferably most, of the nodes change with them.

If you are really interested in learning more about the technical details of a hard fork read this entire thread:  

https://bitcointalk.org/index.php?topic=352734.0

[Fearless]

The bitcoin software is not controlled but it is developed mostly by the group of core developers team pointing towards the easiness in transaction bugs and improvements on the security and while the code is open source anyone could easily manipulate the software and use.

[redsn0w]

If anyone had any control over bitcoin then I would not want them.

This is what i like from bitcoin , no one can control the software . So it is like = anonymous , no leader! This is the new money 

[minerpumpkin]

Your technical explanations and implications for the future of Bitcoin are all true and valid, but it is effectively the miners' decision which rules are enacted. If 75% of the full nodes decide to adhere to a different protocol (some other rules that aren't allowed now, whatever) the Blockchain that's being mined will still adhere to the old rules. Nothing has changed.
Now if miners decide to adhere to that protocol, they effectively create a fork - which fork survives or if both continue to exist is another story.

If 75% of the full nodes decide to adhere to a different protocol, I guarantee you that at least one miner will adhere to the new protocol.  Miners will mine the coins that bring them a profit.  With only 25% of the full nodes accepting, relaying, and broadcasting transactions on the old protocol there will be miners that will switch to the new one.

Therefore, there will be a fork.

But that wasn't the premise I was talking about. You stressed how the full nodes decide about transactions/blocks being accepted and I said that it doesn't matter as long as no miner adheres to those new rules. That it's quite probable that at least one miner will continue to forge the newly forked chain is clear, but that wasn't the premise. Thus, it doesn't matter how many nodes stray from the protocol, as long as they don't also have miners for that chain.

[minerpumpkin]

Your technical explanations and implications for the future of Bitcoin are all true and valid, but it is effectively the miners' decision which rules are enacted. If 75% of the full nodes decide to adhere to a different protocol (some other rules that aren't allowed now, whatever) the Blockchain that's being mined will still adhere to the old rules. Nothing has changed.
Now if miners decide to adhere to that protocol, they effectively create a fork - which fork survives or if both continue to exist is another story.

Evidently you did not grasp the concept that if only the miners change the rules but none of the nodes change with them then the incompatible blocks produced by the rouge miners will all be dropped by all the nodes in the system.

All of those dropped blocks will go nowhere - making the rouge miners no money, while at the same time the unchanged miners get the benefit of the lowered hash rate due to the rogue miners flushing all their hashes down the toilet.

So, the miners will not do that.  They will only change if at least some, preferably most, of the nodes change with them.

If you are really interested in learning more about the technical details of a hard fork read this entire thread:  

https://bitcointalk.org/index.php?topic=352734.0

Yes, I never said anything of the contrary, of course no one cares about my forked chain if I don't also have nodes that relay my mined blocks (and subsequently people that accept that chain to be the 'real' one). I was merely pointing out that it doesn't matter how many nodes stray away as long as there are no miners. In that case, yes, there'll be a hard-fork. Sure. Nothing to see here, effectively a new altcoin.

[foxbitcoin]

Who controls the Bitcoin software?

You do.

You choose what software you are willing to run on your computer.  If a version of the software includes changes that you don't agree with, you can choose not to run it.  If there are specific features that you want in the software, you can either make the changes yourself or you can convince someone else to make the changes for you.

It is decentralized and open source.  All the programming is there for any software programmer to read, study, and modify.

If you try to run software that isn't compatible with the current protocol, then you'll end up with a forked chain.  All the users will then have to choose whether or not they prefer your new-bitcoin over the old-bitcoin.  If they don't prefer what you've done, then your changes will die.  If almost everyone prefers your changes, then the old-bitcoin will die, and yours will replace it.

Is there anything comparable to a "board of directors" for Bitcoin control?

No.  There are various developers of specific wallets (Bitcoin Core, Armory, Electrum, MultiBit, blockchain.info, etc).  Some of them are entirely independent, others answer to some sort of organization that supports that particular wallet.  They all have to adhere to the current protocol unless they can manage to convince the vast majority of users that some change to the protocol would be beneficial.

tks for the explanation

[numismatist]

I have some information for idea:
Bitcoin is the first implementation of a concept called "cryptographic currency", was first described in 1998 by Wei Dai through the codename Cypherpunks, suggests the idea of a new form of currency used honey code to control the creation and trading of it, rather than through a central agency. The specification for the first Bitcoin and proof of concept was published in 2009 through an anonymous nickname Satoshi Nakamoto. Satoshi left the project in late 2010 but did not reveal much about myself. Community has grown exponentially with multiple developers working on Bitcoin.

Grown linearily, with a slight decline recently. Satoshi is identified (according to Wikipedia) as http://en.wikipedia.org/wiki/Satoshi_Nakamoto#Nick_Szabo

[Testing123]

I have some information for idea:
Bitcoin is the first implementation of a concept called "cryptographic currency", was first described in 1998 by Wei Dai through the codename Cypherpunks, suggests the idea of a new form of currency used honey code to control the creation and trading of it, rather than through a central agency. The specification for the first Bitcoin and proof of concept was published in 2009 through an anonymous nickname Satoshi Nakamoto. Satoshi left the project in late 2010 but did not reveal much about myself. Community has grown exponentially with multiple developers working on Bitcoin.

Since the paragraph was copied and pasted directly from https://bitcoin.org/en/faq#who-created-bitcoin. I think you should include the link as well.

Also, the next section on the page is indeed more relevant to the discussion here.

[Gianluca95]

No one. Bitcoin Software is owned by all people of the bitcoin community and all people give some contribution to held the blockchain a better place  . Anyway, Bitcoin Software is totally free, and not managed by someone.