Cốc Cốc browser (previously Cờ Rôm+) is a freeware web browser focused on the Vietnamese market, developed by Vietnamese company Cốc Cốc and based on Chromium open source code, which is the same platform used by Google Chrome, Opera, and Comodo Dragon.
 Cốc Cốc is available for the Windows, Windows Phone and macOS operating systems and supports both English and Vietnamese.
Mozilla Firefox (or simply Firefox) is a free and open-source web browser developed by the Mozilla Foundation and its subsidiary the Mozilla Corporation.
 Firefox is available for Windows, macOS and Linux operating systems, with its Firefox for Android available for Android (formerly Firefox for mobile, it also ran on the discontinued Firefox OS), and uses the Gecko layout engine to render web pages, which implements current and anticipated web standards.
 An additional version, Firefox for iOS, was released in late 2015, but this version does not use Gecko due to Apple's restrictions limiting third-party web browsers to the WebKit-based layout engine built into iOS.
rekonq is a lightweight, QtWebKit-based web browser developed inside the free software project KDE.
 It is the default web browser of Chakra GNU/Linux, and was formerly of Kubuntu (between versions 10.10 and 13.10).
 rekonq has been officially included in KDE Extragear since May 25, 2010.
 In contrast to Konqueror, a web browser and file manager also developed by KDE, rekonq aims to be a standalone and simple web browser.
DuckDuckGo (DDG) is an Internet search engine that emphasizes protecting searchers' privacy and avoiding the filter bubble of personalized search results.
 DuckDuckGo distinguishes itself from other search engines by not profiling its users and by deliberately showing all users the same search results for a given search term.
 DuckDuckGo emphasizes returning the best results, rather than the most results, and generates those results from over 400 individual sources, including key crowdsourced sites such as Wikipedia, and other search engines like Bing, Yahoo!, Yandex, and Yummly.
Rollyo was a Yahoo!-powered search engine which allowed users to register accounts and create personalized search engines.
 Each search engine could include up to 25 websites/blogs chosen by the user.
 Search results were limited to the sites included in a particular search engine.
 Additionally, users could share their "rolled" engines with other contributors or post a mini search box to the user's website using HTML.
 It was also possible to add each "searchroll" to the Mozilla Firefox search bar and to make Rollyo the default search engine for Firefox.
Direct Hit Technologies, Inc. was a Boston-based search engine company that provided search engine services to major web portals and operated a public search engine at directhit.com.
 Founded in April 1998 by Gary Culliss and Mike Cassidy, the Direct Hit search engine utilized the anonymous searching activity of millions of web searchers to rank web sites based on a number of patented algorithms, such as how long searchers spent viewing each web page and where a site was ranked in the original search results list.
 The Direct Hit search engine technology was invented by Gary Culliss and is the subject of the following US Patents: US Pat.
 6,006,222, US Pat.
 6,078,916 and US Pat.
 6,014,665 all entitled "Method for organizing information."
 Direct Hit filed to go public through Robertson Stephens and was acquired by Ask Jeeves in January 2000.
qutebrowser is a web browser for Linux, Windows, and macOS operating systems with vim-style key bindings and a minimal GUI.
 It is keyboard-driven and is inspired by similar software such as Vimperator and dwb.
 It uses DuckDuckGo as the default search engine.
 Qutebrowser is included in the native repositories of Linux distributions such as Fedora and Arch Linux.
A bookmarklet is a bookmark stored in a web browser that contains JavaScript commands that add new features to the browser.
 Bookmarklets are unobtrusive JavaScripts stored as the URL of a bookmark in a web browser or as a hyperlink on a web page.
 Bookmarklets are usually JavaScript programs.
 Regardless of whether bookmarklet utilities are stored as bookmarks or hyperlinks, they add one-click functions to a browser or web page.
 When clicked, a bookmarklet performs one of a wide variety of operations, such as running a search query or extracting data from a table.
 For example, clicking on a bookmarklet after selecting text on a webpage could run an Internet search on the selected text and display a search engine results page.
Opera is a web browser for Windows, macOS, and Linux operating systems developed by Opera Software.
 It uses the Blink layout engine.
 An earlier version using the Presto layout engine is still available, and runs on FreeBSD systems.
 According to Opera, the browser had more than 350 million users worldwide in the 4th quarter of 2014.
 Total Opera mobile users reached 291 million in June 2015.
 According to SlashGeek, Opera has originated features later adopted by other web browsers, including Speed Dial, pop-up blocking, browser sessions, private browsing, and tabbed browsing.
Cliqz is a web browser developed by Cliqz GmbH.
 It is a fork of the Firefox web browser with privacy-oriented changes, among which are a crowdsourced anti-tracking mechanism, and an in-house search engine embedded within the browser, utilizing its own index of web pages to produce suggestions within the address bar dropdown menu rather than on separate pages.
 The browser's developers argued that other privacy-focused search engines may still pass the user's IP address to third-party search providers.
 Cliqz is available as a desktop and mobile web browser, as well as an extension for Firefox itself.

Question: qutebrowser is a web browser for Linux, Windows, and macOS operating systems whose default search engine emphasizes protecting searchers' what?
Answer: privacy