**Important:** uBlock Origin is **NOT** an "ad blocker": [it is a wide-spectrum blocker](https://github.com/gorhill/uBlock/wiki/Blocking-mode) -- which happens to be able to function as a mere "ad blocker". The default behavior of uBlock Origin when newly installed is to block ads, trackers and malware sites -- through [_EasyList_](https://easylist.adblockplus.org/en/policy#easylist), [_EasyPrivacy_](https://easylist.adblockplus.org/en/policy#easyprivacy), [_Peter Lowe’s ad/tracking/malware servers_](http://pgl.yoyo.org/adservers/policy.php), various lists of [malware](http://www.malwaredomainlist.com/) [sites](http://www.malwaredomains.com/), and uBlock Origin's [own filter lists](https://github.com/gorhill/uBlock/tree/master/assets/ublock).
The current reality is that there are *two branches*, not an official one and a lesser one. I [keep developing my branch](https://github.com/gorhill/uBlock/wiki/uBlock-vs.-uBlock-Origin:-Facts#ublock-is-the-main-branch-ublock-origin-is-just-bug-fixes) the same way and in the same spirit I have since [the beginning of uBlock in June 23, 2014](http://www.wilderssecurity.com/threads/ublock-a-lean-and-fast-blocker.365273/), so in substance uBlock Origin _is_ the original uBlock.
**uBlock Origin is _completely_ unrelated to the web site `ublock.org`:** the donations sought by `ublock.org` are _not_ benefiting any of those who contributed most to create uBlock ([developers](https://github.com/gorhill/uBlock/graphs/contributors)<sup>[2]</sup>, [translators](https://crowdin.com/project/ublock), and all those who put efforts in opening detailed issues). For the differences in features between uBlock Origin and uBlock, you are more likely than anywhere else to find an unbiased explanation in this [Wikipedia article](http://en.wikipedia.org/wiki/UBlock).
Somewhere toward the end of May, I decided I will not contribute code anymore to this [uBlock branch](https://github.com/chrisaljoudi/uBlock).<sup>[3]</sup>
<sub>[2] Keep in mind these charts do not take into account all the work done on the wiki (doc, benchmarks), which work was for the most part not contributed by the individual behind `ublock.org`. </sub><br>
<sub>[3] Reasons: [this](https://en.wikipedia.org/w/index.php?title=UBlock&type=revision&diff=662527440&oldid=662107368) vs. [this](https://github.com/chrisaljoudi/uBlock/commits/master?author=gorhill), and [this](https://www.reddit.com/r/ublock/comments/38lf1y/any_difference_between_ublock_and_ublock_origin/crwhmwt), and overall because of serious incompatibilities in the spirit of the project.</sub><br>
[Popup user interface](https://github.com/gorhill/uBlock/wiki/Quick-guide:-popup-user-interface) | [A point-and-click firewall which can be configured on a per-site basis](https://github.com/gorhill/uBlock/wiki/Dynamic-filtering:-quick-guide)
<ahref="https://github.com/gorhill/uBlock/wiki/Quick-guide:-popup-user-interface"><imgsrc="https://raw.githubusercontent.com/gorhill/uBlock/master/doc/img/popup-1.png"/></a><br><sup>.<br>.</sup> | <ahref="https://github.com/gorhill/uBlock/wiki/Dynamic-filtering:-quick-guide"><imgsrc="https://cloud.githubusercontent.com/assets/585534/9293685/378d18f0-4402-11e5-9255-8ed3fdbfa957.png"/></a><br><sup>Configure as you wish:<br>picture shows 3rd-party scripts and frames blocked by default everywhere</sup>
uBlock Origin (or uBlock₀) is not an *ad blocker*; it's a general-purpose blocker. uBlock₀ blocks ads through its support of the [Adblock Plus filter syntax](https://adblockplus.org/en/filters). uBlock₀ [extends](https://github.com/gorhill/uBlock/wiki/Filter-syntax-extensions) the syntax and is designed to work with custom rules and filters. Furthermore, advanced mode allows uBlock₀ to work in [default-deny mode](https://github.com/gorhill/uBlock/wiki/Dynamic-filtering:-default-deny), which mode will cause [all 3rd-party network requests](https://requestpolicycontinued.github.io/#what-are-cross-site-requests) to be blocked by default, unless allowed by the user.
That said, it's important to note that using a blocker is **NOT** [theft](https://twitter.com/LeaVerou/status/518154828166725632). Don't fall for this creepy idea. The _ultimate_ logical consequence of `blocking = theft` is the criminalisation of the inalienable right to privacy.
Ads, "unintrusive" or not, are just the visible portions of privacy-invading apparatus entering your browser when you visit most sites nowadays. **uBlock₀'s main goal is to help users neutralize such privacy-invading apparatus** — in a way that welcomes those users who don't wish to use more technical, involved means (such as [µMatrix](https://github.com/gorhill/uMatrix)).
_EasyList_, _Peter Lowe's Adservers_, _EasyPrivacy_ and _Malware domains_ are enabled by default when you install uBlock₀. Many more lists are readily available to block trackers, analytics, and more. Hosts files are also supported.
Once you install uBlock₀, you may easily un-select any of the pre-selected filter lists if you think uBlock₀ blocks too much. For reference, Adblock Plus installs with only _EasyList_ enabled by default.
<sup>[1] Details of the benchmark available at <ahref="https://github.com/gorhill/uBlock/wiki/Firefox-version:-benchmarking-memory-footprint">Firefox version: benchmarking memory footprint</a>.</sup><br>
<sup>Details of the benchmark available in <ahref="https://github.com/gorhill/uBlock/blob/master/doc/benchmarks/cpu-usage-overall-20141226.ods">this LibreOffice spreadsheet</a>.</sup>
You can install the latest version [manually](https://github.com/gorhill/uBlock/tree/master/dist#install), from the [Chrome Store](https://chrome.google.com/webstore/detail/ublock-origin/cjpalhdlnbpafiamejdnhcphjbkeiagm), or from the [Opera store](https://addons.opera.com/en-gb/extensions/details/ublock/).
[Firefox Add-ons web site](https://addons.mozilla.org/firefox/addon/ublock-origin/). There is also a development version if you want to test uBlock Origin with the latest changes: see [_uBlock Origin Version History_](https://addons.mozilla.org/en-US/firefox/addon/ublock-origin/versions/)
To benefit from uBlock Origin's higher efficiency, it's advised that you don't use other inefficient blockers at the same time (such as AdBlock or Adblock Plus). uBlock₀ will do [as well or better](#blocking) than most popular ad blockers.
