Question: Why does Qutebrowser use DuckDuckGo ?

full_context: Document 1: Visual Studio Code: Visual Studio Code is a source code editor developed by Microsoft for Windows, Linux and macOS. It includes support for debugging, embedded Git control, syntax highlighting, intelligent code completion, snippets, and code refactoring. It is also customizable, so users can change the editor's theme, keyboard shortcuts, and preferences. It is free and open-source, although the official download is under a proprietary license.
Document 2: Bilingual search engine: A bilingual search engine provides multiple language search pages when users type keyword in one language. Obviously, this kind of search engine will give more detailed information for people who speak more than one language, although many mainstream search engines provide multiple languages services. However, the difference between a bilingual search engine and a multiple language search engine is a bilingual search engine will translate keyword from one language to another automatically. Google also published a plug-in (Bilingual Search Suggestion) for Chrome browser to meet the requirement of bilingual search,but it was canceled and unable be found in Chrome web store now.
Document 3: Web query classification: A Web query topic classification/categorization is a problem in information science. The task is to assign a Web search query to one or more predefined categories, based on its topics. The importance of query classification is underscored by many services provided by Web search. A direct application is to provide better search result pages for users with interests of different categories. For example, the users issuing a Web query “"apple"” might expect to see Web pages related to the fruit apple, or they may prefer to see products or news related to the computer company. Online advertisement services can rely on the query classification results to promote different products more accurately. Search result pages can be grouped according to the categories predicted by a query classification algorithm. However, the computation of query classification is non-trivial. Different from the document classification tasks, queries submitted by Web search users are usually short and ambiguous; also the meanings of the queries are evolving over time. Therefore, query topic classification is much more difficult than traditional document classification tasks.
Document 4: Project Shield: Project Shield is a free anti-distributed-denial-of-service (anti-DDoS) service that is offered by Jigsaw, a subsidiary of Google's parent company, Alphabet Inc. to websites that have "media, elections, and human rights related content." The main goal of the project is to serve "small, under-resourced news sites that are vulnerable to the web’s growing epidemic of DDOS attacks", according to team lead George Conard.
Document 5: Qutebrowser: 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.
Document 6: Dandelon.com: Dandelon.com is a collaborative community of libraries in multiple countries as well as a search engine, a search or discovery service, a library information system for the academic community. It is additionally a platform allowing registered libraries to exchange library catalogue enrichment data: tables of content of monographs, deep indexing data, cover pages and bibliographic descriptions of articles published in periodicals, with abstracts and / or full texts provided for part of the items. The domain name was created in 2004. It is derived from the plant dandelion. The name is an allusion to the flower's worldwide occurrence: It is thought to spread around the world as easily as human words and thoughts. Dandelon's aim is to uncover knowledge assets for students from around the world. It is free of charge for private use and without user tracking or advertising.
Document 7: SaferSurf: SaferSurf is a software product for anonymous internet surfing. Aside from offering web anonymity, it has several other features, such as a geolocation proxy service bypassing country restrictions. Its slogan is "Tearing Down Country Borders in the Web". SaferSurf runs centrally on a server and doesn't need a local installation.
Document 8: Yandex Browser: Yandex Browser is a freeware web browser developed by the Russian web search corporation Yandex that uses the Blink web browser engine and is based on the Chromium open source project. The browser checks webpage security with the Yandex security system and checks downloaded files with Kaspersky anti-virus. The browser also uses Opera Software's Turbo technology to speed web browsing on slow connections.
Document 9: Bookmarklet: 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.
Document 10: Deep web: The deep web, invisible web, or hidden web are parts of the World Wide Web whose contents are not indexed by standard search engines for any reason. The content is hidden behind HTML forms. The opposite term to the deep web is the surface web, which is accessible to anyone using the Internet. The deep web includes many very common uses such as web mail and online banking but it also includes services that users must pay for, and which is protected by a paywall, such as video on demand, some online magazines and newspapers, and many more. Computer scientist Michael K. Bergman is credited with coining the term "deep web" in 2001 as a search indexing term.
Document 11: Cliqz: 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.
Document 12: Googlewhack: A Googlewhack is a contest for finding a Google search query consisting of exactly two words without quotation marks, that returns exactly one hit. A Googlewhack must consist of two actual words found in a dictionary. A Googlewhack is considered legitimate if both of the searched-for words appear in the result page. For example, typing an asterisk (*) into the Google Search Bar turns up no results.
Document 13: Safari (web browser): Safari is a web browser developed by Apple based on the WebKit engine. First released in 2003 with Mac OS X Panther, a mobile version has been included in iOS devices since the introduction of the iPhone in 2007. It is the default browser on Apple devices. A Windows version, now discontinued, was available from 2007 to 2012.
Document 14: DuckDuckGo: 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.
Document 15: KHTML: KHTML is a HTML layout engine developed by the KDE project. It is the engine used by the Konqueror web browser. Descendants of KHTML are used by some of the world's most widely used browsers, among them Google Chrome, Safari and Opera. Distributed under the terms of the GNU Lesser General Public License, KHTML is free software.
ground_truth: emphasizes returning the best results