A free and open source web browser.

# To launch Firefox and open a web page:
firefox <https://www.duckduckgo.com>

# To open a new window:
firefox --new-window <https://www.duckduckgo.com>

# To open a private (incognito) window:
firefox --private-window

# To search for "wikipedia" using the default search engine:
firefox --search "<wikipedia>"

# To launch Firefox in safe mode, with all extensions disabled:
firefox --safe-mode

# To take a screenshot of a web page in headless mode:
firefox --headless --screenshot <path/to/output_file.png> <https://example.com/>

# To use a specific profile directory to allow multiple separate instances of Firefox to run at once:
firefox --new-instance --profile <path/to/directory> <https://example.com/>