View source for Software:Bitcoin XT

{{Infobox software
| name = Bitcoin XT
| logo = Bitcoinxt.png
| screenshot = 
| caption = 
| developer = 
| author = 
| released = August 15, 2015
| latest release version = Release I
| latest release date = {{Start date and age|2018|04|22|df=yes}}
| discontinued = Yes
| programming_language = 
| operating_system =
| genre = [[Finance:Cryptocurrency|Cryptocurrency]]
| license = [[Software:MIT License|MIT License]]
| website = {{URL|https://bitcoinxt.software/}}
| repo = {{url|https://github.com/bitcoinxt/bitcoinxt}}
}}
'''Bitcoin XT''' was<ref name=obsolete>https://github.com/bitcoinxt/bitcoinxt/releases/tag/v0.11K, https://honest.cash/v2/dgenr8/xt-wont-follow-may-19-bch-fork-4313</ref> a [[Software:Fork (software development)|fork]] of [[Software:Bitcoin Core|Bitcoin Core]], the [[Reference implementation|reference client]] for the [[Finance:Bitcoin network|bitcoin network]]. In mid-2015, the concept achieved significant attention within the bitcoin community amid a contentious debate among core developers over increasing the block size cap.<ref name="Hern-2015">{{cite news|url=https://www.theguardian.com/technology/2015/aug/17/bitcoin-xt-alternative-cryptocurrency-chief-scientist|title=Bitcoin's forked: chief scientist launches alternative proposal for the currency|author=Alex Hern|date=2015-08-17|newspaper=the Guardian|accessdate=20 August 2015}}</ref>  The current reference implementation for bitcoin contains a computational [[Social:Bottleneck (production)|bottleneck]].<ref name="inth">{{Cite news |url=http://www.newyorker.com/business/currency/inside-the-fight-over-bitcoins-future |title=Inside the Fight Over Bitcoin’s Future |author= |accessdate=7 January 2017 |date=25 August 2015 |newspaper=The New Yorker |publisher=Conde Naste }}</ref>

This averages to a daily maximum of around 300,000 transactions.<ref name="diov">{{Cite news |url=https://www.extremetech.com/computing/212919-disagreement-over-bitcoins-future-threatens-to-fork-the-currency |title=Disagreement over Bitcoin’s future threatens to fork the currency |author=Ryan Whitwam |accessdate=7 January 2017 |date=25 August 2015 |work=Extreme Tech |publisher=Ziff Davis, LLC}}</ref>

It was proposed that the block size increase to eight megabytes, and from then onwards to automatically increase it exponentially, doubling every two years. The proposal did not gain the necessary support to go into effect on the Bitcoin network by early 2016, the earliest possible switchover date. Its use has been in steady decline from March 2016 onwards.

As of August 2017, Bitcoin XT is a [[Finance:Bitcoin Cash|Bitcoin Cash]] client by default.<ref name="releases">{{cite web|url=https://github.com/bitcoinxt/bitcoinxt/releases|title=Bitcoin XT Releases|accessdate=17 June 2018}}</ref>

==History==
On June 10, 2014 Mike Hearn published a ''Bitcoin Improvement Proposal'' (BIP 64), calling for the addition of "a small P2P protocol extension that performs UTXO lookups given a set of outpoints."<ref>{{cite web|url=https://github.com/bitcoin/bips/blob/master/bip-0064.mediawiki|title=bips/bip-0064.mediawiki at master · bitcoin/bips · GitHub|work=GitHub}}</ref>  On December 27, 2014 Hearn released version 0.10 of the [[Client (computing)|client]], with the BIP 64 changes.<ref>{{cite web|url=https://github.com/bitcoinxt/bitcoinxt/releases/tag/v0.10|title=bitcoinxt/bitcoinxt|website=GitHub}}</ref>

On June 22, 2015, Gavin Andresen published BIP 101 calling for an increase in the maximum block size. The changes would activate a fork allowing eight MB blocks (doubling in size every two years) once 75% of a stretch of 1,000 mined blocks is achieved after the beginning of 2016.<ref>{{cite web|url=https://github.com/bitcoin/bips/blob/master/bip-0101.mediawiki|title=bips/bip-0101.mediawiki at master · bitcoin/bips · GitHub|work=GitHub}}</ref> The new maximum transaction rate under XT would have been 24 transactions per second.<ref name="edov">{{Cite news |url=http://www.pcworld.com/article/2974339/bitcoin-xt-debate-overshadowing-growth-opportunities.html |title=Bitcoin XT debate overshadowing growth opportunities |author=Tim Hornyak |accessdate=7 January 2017 |date=21 August 2015 |work=PC World |publisher=IDG }}</ref>

On August 6, 2015 Andresen's BIP101 proposal was merged into the XT [[Codebase|codebase]].<ref>{{cite web|url=https://github.com/bitcoinxt/bitcoinxt/commit/946e3ba8c7806a66c2b834d3817ff0c986c0811b|title=Implement hard fork to allow bigger blocks · bitcoinxt/bitcoinxt@946e3ba|website=GitHub}}</ref><ref>{{cite web|url=https://github.com/bitcoinxt/bitcoinxt/releases/tag/v0.11A|title=bitcoinxt/bitcoinxt|website=GitHub}}</ref> Bip 101 was reverted<ref>{{cite web|url=https://github.com/bitcoinxt/bitcoinxt/pull/117|title=2MB block size bump by dgenr8 · Pull Request #117 · bitcoinxt/bitcoinxt|website=GitHub}}</ref> and the 2-MB block size bump of [[Software:Bitcoin Classic|Bitcoin Classic]] was applied instead.

== Reception ==
The August 2015 release of XT received widespread media coverage. ''{{wipe|The Guardian}}'' wrote that "bitcoin is facing civil war".<ref name="Hern-2015" />

''Wired'' wrote that "Bitcoin XT exposes the extremely social — extremely democratic — underpinnings of the open source idea, an approach that makes open source so much more powerful than technology controlled by any one person or organization."<ref>{{cite news|url=https://www.wired.com/2015/08/bitcoin-schism-shows-genius-open-source/|title=The Bitcoin Schism Shows the Genius of Open Source|date=19 August 2015|work=WIRED|author=Cade Metz}}</ref> Developer [[Biography:Adam Back|Adam Back]] was critical of the 75% activation threshold being too low and that some of the changes were insecure.<ref name="bisp">{{Cite news |url=https://www.cnbc.com/2015/08/20/bitcoin-splits-will-it-break-or-be-better-than-ever.html |title=Bitcoin splits: Will it break, or be better than ever? |author=Everett Rosenfeld |accessdate=5 January 2017 |date=20 August 2015 |work=CNBC }}</ref>

==Bitcoin Cash support==

On August 25, 2017, Bitcoin XT published ''Release G'', which was a [[Finance:Bitcoin Cash|Bitcoin Cash]] client by default.<ref name="releases" /> Subsequently, ''Release H'' was published, which supported the November 2017 Bitcoin Cash protocol upgrade, followed by ''Release I'', which supported the May 2018 Bitcoin Cash protocol upgrade.

==See also==

*[[Finance:List of bitcoin forks|List of bitcoin forks]]
*[[Software:List of software forks|List of software forks]]
*[[Finance:Bitcoin scalability problem|Bitcoin scalability problem]]

==References==
{{Reflist|2}}

== External links ==
* [https://github.com/bitcoinxt/bitcoinxt Bitcoin XT] on [[GitHub]]

{{Bitcoin|state=expanded}}

[[Category:Bitcoin clients]]
[[Category:Free software]]

{{Sourceattribution|Bitcoin XT|1}}