Some Excerpts From My Emacs Config

(defvar my/os-linux (string-equal system-type "gnu/linux") "I'm on Linux")
(defvar my/os-macos (string-equal system-type "darwin") "Oh, I'm on macOS")
(defvar my/os-windows (string-equal system-type "windows-nt") "OMG, that's Windows!")

;; Disable Command key and enable Options as Meta.
(if my/os-macos
    (setq mac-command-key-is-meta nil
          mac-command-modifier 'super
          mac-option-key-is-meta t
          mac-option-modifier 'meta))

(set-language-environment 'utf-8)
(setq locale-coding-system 'utf-8)
(setq buffer-file-coding-system 'utf-8-unix)
(set-terminal-coding-system 'utf-8)
(set-keyboard-coding-system 'utf-8)
(set-selection-coding-system 'utf-8)
(prefer-coding-system 'utf-8)

(setq scroll-step 1)

;; Marker distance from center (don't jump to center).
(setq scroll-conservatively 100000)

;; Try to keep screen position when PgDn/PgUp.
(setq scroll-preserve-screen-position 1)

;; Start scrolling when marker at top/bottom.
(setq scroll-margin 0)

;; Mouse scroll moves 1 line at a time, instead of 5 lines.
(setq mouse-wheel-scroll-amount '(1))

;; On a long mouse scroll keep scrolling by 1 line.
(setq mouse-wheel-progressive-speed nil)

;; Non-nil means cutting and pasting uses the clipboard.
(setq x-select-enable-clipboard t)

;; No ToolBar, please.
(tool-bar-mode -1)

;; No alarms, please.
(setq ring-bell-function 'ignore)

;; No lock files, please.
;; https://emacs.stackexchange.com/questions/78800/how-to-disable-automatic-appearance-of-warnings-buffer-in-emacs
(setq create-lockfiles nil)

;; Sentences do not need double spaces to end. Period.
(set-default 'sentence-end-double-space nil)

;; Replace "yes" by "y".
(fset 'yes-or-no-p 'y-or-n-p)

;; Don’t use dialog boxes.
(setq use-dialog-box nil)

;; For gpg (works on Ubuntu and macOS) to disable custom prompt.
(setenv "GPG_AGENT_INFO" nil)

;; Speedup cursor movement.
;; https://emacs.stackexchange.com/questions/28736/emacs-pointcursor-movement-lag/28746
(setq auto-window-vscroll nil)

;; Spaces instead of tabs when indenting.
;; Some people may not agree with this though.
(setq-default indent-tabs-mode nil)

;; Nonzero means echo unfinished commands after this many seconds of
;; pause. The value may be integer or floating point. If the value is
;; zero, don’t echo at all.
(setq echo-keystrokes 0.01)

;; Winner mode is a global minor mode that records the changes in the
;; window configuration.
;; https://www.gnu.org/software/emacs/manual/html_node/emacs/Window-Convenience.html
(winner-mode t)

;; Turn on highlighting current line.
;; http://ergoemacs.org/emacs/emacs_make_modern.html
(global-hl-line-mode 1)

;; Replace highlighted text with what I type rather than just
;; inserting at point.
(delete-selection-mode t)

;; Restore opened files.
(desktop-save-mode 1)

;; Save minibuffer history.
(savehist-mode 1)

;; When on a tab, make the cursor the tab length.
(setq-default x-stretch-cursor t)

;; Auto refresh dired when file changes.
;; http://pragmaticemacs.com/emacs/automatically-revert-buffers/
(add-hook 'dired-mode-hook 'auto-revert-mode)

;; Auto refresh dired, but be quiet about it.
(setq global-auto-revert-non-file-buffers t)
(setq auto-revert-verbose nil)

;; Automatically reload files was modified by external program.
;; https://www.emacswiki.org/emacs/AutoRevertMode
(global-auto-revert-mode 1)

;; Make URLs in comments/strings clickable, (Emacs > v22).
(add-hook 'find-file-hooks 'goto-address-prog-mode)

;; Display fringe indicators in `visual-line-mode`.
(setq visual-line-fringe-indicators '(left-curly-arrow right-curly-arrow))

;; Switching the focus to the help window when it's opened.
(setq help-window-select t)

;; Frame title.
(setq frame-title-format "%F--%b-[%f]--%Z")

;; Global.
(electric-pair-mode 1)

(defvar calendar-latitude NN.N)
(defvar calendar-longitude NN.N)

;; Number of minutes difference between local standard time and UTC.
;; For example, -300 for New York City, -480 for Los Angeles.
(defvar calendar-time-zone NNN)

;; Optional, the default value is just the variable `calendar-latitude`
;; paired with the variable `calendar-longitude`.
(defvar calendar-location-name "Your City, Your Country")

;; First day of the week: 0:Sunday, 1:Monday.
(defvar calendar-week-start-day 1)

;; Use European date format (DD/MM/YYYY or 9 October 2024).
(defvar calendar-date-style 'european)