Firefox

Install the package:

# aptitude install firefox-esr

This browser may be configured for your regular user, in order to meet your needs:

$ firefox

Right click on the Toolbar and enable the Menu Bar, but not the Bookmarks Toolbar (Only Show on New Tab).

First of all, select Extensions and Themes from the Tools menu. In the Themes section, enable the Light theme.

Select Settings from the Edit menu. In the "General" section, check "Open previous windows and tabs", uncheck "Always check if Firefox is your default browser", uncheck "Ctrl+Tab cycles through tabs in recently used order", check "Open links in tabs instead of new windows", uncheck "When you open a link, image or media in a new tab, switch to it immediately", uncheck "Ask before closing multiple tabs", check "Ask before quitting with Ctrl+Q", check "Show an image preview when you hover on a tab"; choose browser layout "Horizontal tabs"; choose website appearance "Automatic"; choose contrast control "Automatic (use system settings)"; choose Default font "sans-serif", size "16", then click on the "Advanced..." button and choose fonts for "Latin" (Proportional "Sans Serif", Size "16", Serif "serif", Sans-serif "sans-serif", Monospace "monospace", Size "12", Minimum font size "9", check "Allow pages to choose their own fonts, instead of your selections above"); select Default zoom "100 %", uncheck "Zoom text only"; select language "English (US)" and click on the "Choose..." button and configure languages (en-us, en, it), uncheck "Check your spelling as you type"; leave translations settings untouched; choose Save files to "Downloads", uncheck "Always ask you where to save files", leave all the applications entries as they are, except for mailto, where you may select "Use other...", click on the "Type a file name" button (if needed), and enter "/usr/bin/xdg-email", choose "Save files" with other files, uncheck "Play DRM-controlled content"; check "Use recommended performance settings"; check "Use autoscrolling", check "Use smooth scrolling", uncheck "Always show scrollbars", uncheck "Always use the cursor keys to navigate within pages", uncheck "Always underline links", uncheck "Search for text when you start typing", check "Enable picture-in-picture video controls", check "Control media via keyboard, headset, or virtual interface", uncheck "Recommend extensions as you browse", uncheck "Recommend features as you browse"; click on the Network Settings "Settings..." button and choose "Use system proxy settings".

In the "Home" section, select Homepage and new windows "Blank Page", select New tabs "Blank Page", in Firefox Home Content check "Web Search", uncheck "Shortcuts", uncheck "Recent activity".

In the "Search" section, select "DuckDuckGo" as Default Search Engine, uncheck "Show search suggestions", uncheck "Show recent searches", uncheck address bar suggestions from "Browsing history", "Bookmarks", "Open tabs", "Shortcuts", "Search engines", "Quick actions", and remove all the alternative search shortcuts that you can.

In the "Privacy & Security" section, choose "Custom" Enhanced Tracking Protection, and check "Cookies" selecting "All cross-site cookies (may cause websites to break)", check "Tracking content" selecting "In all windows", check "Cryptominers", check "Known fingerprinters", check "Suspected fingerprinters" selecting "Only in private windows"; check "Tell websites not to sell or share my data"; check "Delete cookies and site data when Firefox is closed", uncheck "Ask to save passwords", check "Show alerts about passwords for breached websites", uncheck "Use a Primary Password"; uncheck "Save and fill payment methods"; select Firefox will "Use custom settings for history", uncheck "Always use private browsing mode", check "Remember browsing and download history", check "Remember search and form history", check "Clear history when Firefox closes", and click on the "Settings..." button (automatically clear all checked items when Firefox closes: uncheck "Browsing & download history", check "Cookies and site data", check "Temporary cached files and pages", uncheck "Saved form info", uncheck "Site settings"); check "Block pop-up windows" (you can add exceptions for specific websites, if needed), check "Warn you when websites try to install add-ons" (remove all the exceptions, if any); uncheck "Send technical and interaction data to Mozilla", uncheck "Allow personalized extension recommendations", uncheck "Install and run studies" (these two settings should already be disabled in the Debian package), uncheck "Send daily usage ping to Mozilla", uncheck "Automatically send crash reports"; uncheck "Allow websites to perform privacy-preserving ad measurement"; uncheck "Block dangerous and deceptive content", check "Query OCSP responder servers to confirm the current validity of certificates", choose "Enable HTTPS-Only Mode in all windows", choose DNS over HTTPS "Default Protection".

In the "Sync" section, don't do anything.

From the View menu, Toolbars entry, leave Menu Bar checked, but not Bookmarks Toolbar (Only Show on New Tab). From the View menu, Sidebar entry, check Bookmarks and adjust the horizontal size of the sidebar; leave History, Synced Tabs, and AI chatbot unchecked.

From the Bookmarks menu click on "Manage Bookmarks": You can import bookmarks previously exported from another browser in HTML format, by using the "Import and Backup" menu of the dialog window.

In order to easily querying Debian-related pages, install the following extension:

# aptitude install webext-debianbuttons

After restarting the browser for your regular user, click on the Extensions button in your navigation toolbar and click on "pin to the toolbar" for the Debian queries extension. Then, customize your navigation toolbar, by selecting Customize Toolbar... from the View menu, Toolbars entry. Drag the Debian button within the navigation toolbar (move it just after the home button).

If you want Firefox to be your default web browser, you can add the following two lines to your ~/.bashrc:

$ grep -i browser ~/.bashrc
# set a sensible browser
export BROWSER="firefox"

This way, a new Firefox tab will be opened whenever some other application invokes the sensible-browser command on a URI.

Moreover, you may want to elect Firefox as your default viewer for (X)HTML and XML documents and as your default handler for the HTTP(S) protocol. First of all, install the following package (if it is not already installed):

# aptitude install xdg-utils

Then, issue the following command:

$ xdg-mime default firefox-esr.desktop \
   text/html text/xml application/xhtml+xml application/xml \
   application/vnd.mozilla.xul+xml application/rss+xml application/rdf+xml \
   x-scheme-handler/http x-scheme-handler/https

Chromium

Install the package:

# aptitude install chromium avahi-utils_

Now configure the browser for your regular user:

$ chromium

Click on the "Customize and control Chromium" button and select Settings from the drop down menu. In the "Privacy and security" section, make sure third-party cookies are blocked. In the "Appearance" section, choose "New Tab page" as home page and enable "Show home button". In the "Search engine" section, choose "DuckDuckGo" as search engine used in the address bar. In the "On startup" section, choose "Open the New Tab page". In the "Languages" section, set "1. English (United States), 2. English, 3. Italian" as languages, disable spell check and Google Translate. In the "System" section, disable "Continue running background apps when Chromium is closed", enable "Use graphics acceleration when available".

Falkon

Install the package:

# aptitude --without-recommends install falkon

Now configure the browser for your regular user:

$ falkon

Click on the "Tools" button on the far right and, from the Toolbars menu, check "Menu Bar", check "Navigation Toolbar", uncheck "Bookmarks Toolbar", check "Tabs on Top". From the Sidebars menu, select Bookmarks and customize the sidebar width to fit your needs.

Select Preferences from the Edit menu. In the "General" section, select "Restore session" after launch, set "about:blank" as homepage, select "Open blank tab" on new tab, check "Don't load tabs until selected", select "default" startup profile.

In the "Appearance" section, "Themes" tab, select "Linux". In the "Advanced options" tab, uncheck "Show StatusBar on start", uncheck "Show Bookmarks ToolBar on start", check "Show Navigation ToolBar on start", uncheck "Enable instant Bookmarks ToolBar".

In the "Tabs" section, "Tabs behaviour" tab, uncheck "Hide tabs when there is only one tab", uncheck "Activate last tab when closing active tab", check "Open new tabs after active tab", uncheck "Open new empty tabs after active tab", check "Open popup windows in tabs", uncheck "Always switch between tabs with mouse wheel", uncheck "Automatically switch to newly opened tab", uncheck "Don't close window upon closing last tab", check "Ask when closing multiple tabs", check "Show closed tabs button", select "Always" show close buttons on inactive tabs. In the "Address Bar behaviour" tab, select "Nothing" suggest when typing into address bar, uncheck "Enable inline suggestions", uncheck "Propose to switch tab if completed url is already loaded", check "Always show go icon", check "Show zoom label", check "Select all text by double clicking in address bar", uncheck "Select all text by clicking in address bar", uncheck "Enable automatic searching from the address bar", uncheck "Expand suggestion popup to window width", check "Show loading progress in address bar", select "Fill", uncheck "Custom color".

In the "Browsing" section, "Web Configuration" tab, uncheck "Allow Pepper Plugin API (PPAPI)", check "Allow JavaScript", uncheck "Include links in focus chain", check "Enable XSS Auditing", check "Print element background", check "Animated scrolling", uncheck "Enable spatial navigation", uncheck "Use native scrollbars", check "Disable automatic playing of videos", check "Prevent WebRTC from leaking local IP address", check "Enable DNS prefetching", check "Enable screen capture", check "Use hardware acceleration (requires restart)". In the "Local Storage" tab, check "Allow storing network cache on disk", check "Delete cache on close", set "50 MB" maximum, set "${HOME}/.cache/falkon/default" store cache (where ${HOME} is your user's home directory), check "Allow saving history", uncheck "Delete history on close", check "Allow local storage of HTML5 web content", uncheck "Delete locally stored HTML5 web content on close". In the "Proxy Configuration" tab, choose "System proxy configuration".

In the "Fonts" section, set "Sans Serif" as standard font, "Monospace" as fixed, "Serif" as serif, "Sans Serif" as sans serif, "Z003 [urw]" as cursive, "D050000L [urw]" as fantasy; set "16" default font size, "12" fixed font size, "9" minimum font size, "10" minimum logical font size.

In the "Keyboard Shortcuts" section, check "Switch to tabs with Alt + number of tab", uncheck "Load speed dials with Ctrl + number of speed dial", uncheck "Use single key shortcuts", check "Close application with Ctrl-Q".

In the "Downloads" section, choose "Use defined location:" and set "${HOME}/Downloads", check "Close download manager when downloading finishes", uncheck "Use external download manager".

In the "Password Manager" section, uncheck "Allow saving passwords from sites", uncheck "Automatically complete passwords on sites".

In the "Privacy" section, "General" tab, click on the "Cookies Manager" button and (in the "Settings" tab of the dialog window) check "Allow storing of cookies", uncheck "Filter tracking cookies", uncheck "Filter 3rd party cookies", check "Delete cookies on close"; click on the "Javascript options" button and uncheck "Open popup windows", uncheck "Activate windows", check "Access clipboard", check "Paste from clipboard"; check "Send Do Not Track header to servers". In the "HTML5 Permissions" tab, select "Ask" for all the entries. In the "Site Settings" tab, you can configure site-specific permissions/restrictions, as needed.

In the "Notifications" section, choose "Do not use Notifications".

In the "Extensions" section, enable "AdBlock", enable "AutoScroll", disable all the other extensions.

In the "Spell Check" section, uncheck "Enable Spell Check".

In the "Other" section, click on the "Languages" button and add "Italian/Italy [it-it]" after "English/United States [en-US]" and "English/United States [en]"; click on the "User Agent Manager" button and uncheck "Change global User Agent" (here you can configure site-specific user agents, as needed); click on the "Search Engines Manager" and remove all the search engines, except for "DuckDuckGo" and "StartPage" (which can be set as default); you can the other buttons in order to set other site-specific rules.

w3m

Install the package:

# aptitude install w3m-img