If you're a developer, you will want to setup a development environment with all the tools, libraries and support software for writing bitcoin applications. If you're not a developer, you might want to skip this chapter entirely.
=== Bitcoin Core: The Reference Implementation
((("bitcoin client", id="ix_ch03-asciidoc0", range="startofrange")))((("bitcoin client","Bitcoin Core", id="ix_ch03-asciidoc1", range="startofrange")))((("Bitcoin Core client", id="ix_ch03-asciidoc2", range="startofrange")))((("Satoshi client", see="Bitcoin Core client")))You can download the reference client _Bitcoin Core_, also known as the "Satoshi client," from bitcoin.org. The reference client implements all aspects of the bitcoin system, including wallets, a transaction verification engine with a full copy of the entire transaction ledger (blockchain), and a full network node in the peer-to-peer bitcoin network.
Bitcoin is an _open source_ project and the source code is available under an open (MIT) license, free to download and use for any purpose. Open source means more than simply free to use. It also means that bitcoin is developed by an open community of volunteers. At first, that community consisted of only Satoshi Nakamoto. By 2016, bitcoin's source code has more than 340 contributors with about a dozen developers working on the code almost full time and several dozen more on a part-time basis. Anyone can contribute to the code - including you!
When bitcoin was created by Satoshi Nakamoto, the software was actually completed before the white paper <<satoshi_whitepaper>>. Satoshi wanted to make sure it worked before writing about it. That first implementation, then simply known as "Bitcoin" or "Satoshi client" has been heavily modified and improved. It has evolved into what is known as _Bitcoin Core_, to differentiate it from other compatible implementations. Bitcoin Core is the _reference implementation_ of the bitcoin system, meaning that it is the authoritative reference on how each part of the technology should be implemented. Bitcoin Core implements all aspects of bitcoin, including wallets, a transaction and block validation engine, and a full network node in the peer-to-peer bitcoin network.
On((("bitcoin.org","Bitcoin Core, downloading"))) http://bitcoin.org/en/choose-your-wallet[Bitcoin's Choose Your Wallet page], select Bitcoin Core to download the reference client. Depending on your operating system, you will download an executable installer. For Windows, this is either a ZIP archive or an .exe executable. For Mac OS it is a .dmg disk image. Linux versions include a PPA package for Ubuntu or a tar.gz archive. The bitcoin.org page that lists recommended bitcoin clients is shown in <<bitcoin-choose-client>>.
You can download an executable release of Bitcoin Core for your operating system, or you can build your own executable directly from the source code (see <<compiling_core>>). If you're a developer you should probably try and build your own copy of Bitcoin Core, to see how the build process works. Perhaps one day you too might contribute source code to bitcoin and learning how to build it is the first step towards that goal.
On((("bitcoin.org","Bitcoin Core, downloading"))) http://bitcoin.org/en/choose-your-wallet[Bitcoin's Choose Your Wallet page], select Bitcoin Core to download the reference client. Depending on your operating system, you will download an executable installer or package. For Windows, this is either a ZIP archive or an .exe executable. For Mac OS it is a .dmg disk image. Linux versions include a PPA package for Ubuntu or a tar.gz archive.
==== Running Bitcoin Core for the First Time
@ -23,12 +27,13 @@ image::images/msbt_0302.png["bitcoin-qt first run"]
[TIP]
====
((("Bitcoin Core client","disk space requirement for")))((("blockchains","synchronizing for Bitcoin Core")))((("disk space requirement for Bitcoin Core")))Bitcoin Core keeps a full copy of the transaction ledger (blockchain), with every transaction that has ever occurred on the bitcoin network since its inception in 2009. This dataset is several gigabytes in size (approximately 16 GB in late 2013) and is downloaded incrementally over several days. The client will not be able to process transactions or update account balances until the full blockchain dataset is downloaded. During that time, the client will display "out of sync" next to the account balances and show "Synchronizing" in the footer. Make sure you have enough disk space, bandwidth, and time to complete the initial synchronization.
((("Bitcoin Core client","disk space requirement for")))((("blockchains","synchronizing for Bitcoin Core")))((("disk space requirement for Bitcoin Core")))Bitcoin Core keeps a full copy of the transaction ledger (blockchain), with every transaction that has ever occurred on the bitcoin network since its inception in 2009. This dataset is several gigabytes in size (approximately 66 GB in early 2016) and is downloaded incrementally over several days. The client will not be able to process transactions or update account balances until the full blockchain dataset is downloaded. During that time, the client will display "out of sync" next to the account balances and show "Synchronizing" in the footer. Make sure you have enough disk space, bandwidth, and time to complete the initial synchronization.
====
[[compiling_core]]
==== Compiling Bitcoin Core from the Source Code
((("Bitcoin Core client","compiling from source code", id="ix_ch03-asciidoc3", range="startofrange")))((("bitcoind client", see="Bitcoin Core client")))For developers, there is also the option to download the full source code as a ZIP archive or by cloning the authoritative source repository from GitHub. ((("Bitcoin Core client","source code, downloading")))((("GitHub, downloading Bitcoin Core from"))) On the https://github.com/bitcoin/bitcoin[GitHub bitcoin page], select Download ZIP from the sidebar. Alternatively, use the git command line to create a local copy of the source code on your system. In the following example, we are cloning the source code from a Unix-like command line, in Linux or Mac OS:
Andreas M. Antonopoulos
8 years ago