µBlock is not an *ad blocker*; it's a general-purpose blocker. µBlock blocks ads through its support of the [Adblock Plus filter syntax](https://adblockplus.org/en/filters). µBlock [extends](https://github.com/gorhill/uBlock/wiki/Filter-syntax-extensions) the syntax and is designed to work with custom rules and filters.
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. **µBlock'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_ are enabled by default when you install µBlock. Many more lists are readily available to block trackers, analytics, and more. Hosts files are also supported.
<sup>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>
<sup>**Important note regarding memory usage:** There is currently a [bug in Chromium 39+ which causes a new memory leak each time the popup UI of an extension is opened](https://code.google.com/p/chromium/issues/detail?id=441500). This affects *all* extensions. Keep this in mind when measuring Chromium's memory usage. In the benchmarks, I avoided opening the popups completely.</sup>
<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 Web Store](https://chrome.google.com/webstore/detail/cjpalhdlnbpafiamejdnhcphjbkeiagm), or from the [Opera store](https://addons.opera.com/en-gb/extensions/details/ublock/).
You can install by downloading the latest [uBlock.firefox.xpi](https://github.com/gorhill/uBlock/releases) file, and by dragging the downloaded `xpi` file to your add-on page.
You can get µBlock for Safari (Yosemite's 8.0 or newer) from the [Safari Extension Gallery](https://extensions.apple.com/details/?id=net.gorhill.uBlock-96G4BAKDQ9).
To benefit from µBlock's higher efficiency, it's advised that you don't use other inefficient blockers at the same time (such as AdBlock or Adblock Plus). µBlock will do [as well or better](#blocking) than most popular ad blockers.
µBlock's functionality is self-explanatory and intuitive for the most part. One thing to note after you get started is the big power button in µBlock's popup:
**In other words, it applies to the current site only; it is *not* a global power button.** The state of the power switch for a specific site will be remembered.
For advanced usage, read about [dynamic filtering](https://github.com/gorhill/uBlock/wiki/Dynamic-filtering:-quick-guide) and more on [µBlock's wiki](https://github.com/gorhill/uBlock/wiki).
