In the Wolfram System, a palette is just a notebook with a collection of controls such as buttons. A uniquely powerful consequence of the Wolfram Language's unified design is that a symbolic specification, easily built up by a program, can immediately be deployed as an active palette.

Palettes ▶ — menu of built-in and custom-added palettes

Install Palette — add a palette to the Palettes menu

CreatePalette — create a palette from an expression, and open it on screen

Palette Elements

Button — a button with any label and any action

PasteButton — a button which pastes its contents at the current selection

Appearance — option to specify button appearance (e.g., "Palette")

FileNameSetter  ▪  ColorSlider  ▪  PopupMenu

PaletteNotebook — symbolic representation of a complete palette

Layout

Column  ▪  Grid  ▪  Spacings  ▪  OpenerView  ▪  MenuView  ▪  TabView

Annotation & Styling

Tooltip  ▪  Mouseover  ▪  StatusArea  ▪  Labeled  ▪  Panel  ▪  Style  ▪  Speak

Window Options »

WindowTitle  ▪  WindowMargins  ▪  WindowOpacity  ▪  ClosingAutoSave  ▪  ...

Palette Actions »

SetOptions  ▪  NotebookApply  ▪  Print  ▪  CreateDocument  ▪  NotebookFind  ▪  ...