Paint
Sprites
A sprite is an animation made from a run of frames or artboards. Select one or more frames, right-click and choose Create Sprite from Frame; they play in reading order, left to right and top to bottom. Right-click an artboard and choose Create sprite from artboards to make one from every artboard, or Add to sprite to add frames or artboards to one you have. The Sprites panel lists them.
A sprite has a frame rate, or a time for each sprite frame, and plays once, loops, or plays back and forth (Ping-pong). Its Timing is Time, each sprite frame lasting so many milliseconds, or Frames, each lasting so many frames of the timeline it plays on, so it plays faster on a faster timeline. A sprite frame can be timed the other way from the rest with the unit beside its length, and a frame or artboard's Properties shows its length in every sprite it's in.
When the timeline it's on has a length, Fit to the timeline plays a sprite or a program embed faster or slower so its plays fill the timeline from where it starts. A program embed's Length sets how long it plays each time, in seconds or frames, in place of the program's own; a program that runs on has a length to loop and fit only once it's given one.
Everything that moves plays on the artwork's own clock, shown in the Timeline, which is offered once the artwork has a sprite with sprite frames, a program embed or a frame with a timeline of its own: play and pause (also Space), back to the start (also ⌘←, with ⌘→ to the end, when no artboard is selected), a frame back or on, and the time. Paused, every sprite holds its sprite frame. Whether it was playing is remembered per artwork, and an artwork opening waits until its program embeds have frames ready.
The timeline's frame rate, its length and what it does at the end are saved with the artwork. The window grows with its tracks; once you've resized its height, double-click its resize corner or edge to let it fit them again. Its pin fixes it along the bottom of the window, full width, over the canvas, with play as a large square in its corner; drag its top row to resize it, double-click that row to fit the tracks again, and its pin floats it again. Each artwork remembers which it uses. Scroll sideways to move along time, and ⌘-scroll to zoom. Drag the playhead's grip, or the ruler's foot, to scrub; a click anywhere on the ruler moves the playhead. Drag along the ruler's labels to mark a work region: while the playhead is inside it, play loops over it, and play that starts past it runs on as if it weren't there. Drag the region's ends to resize it or its middle to move it, and drag it down to nothing to clear it. Drag a track's bar to move where it starts; before its start it holds its first frame. Click a track's loop mark to switch whether it loops. Right-click a track to choose how many times it Plays, or Timeline ends with this track to end the timeline where that track ends (after its first cycle, when it loops for ever).
A frame can have a timeline of its own: choose Add timeline under Timeline in its Properties. What moves inside it then plays on that timeline, and the frame is one track on the timeline holding it, with its own length, plays and start, set in the Timeline window. Configure timeline, a double-click on its track's name, or Open its timeline on the track's right-click menu shows what plays inside; the window's title then shows the path to it, and pressing a name in it goes back out. Switching it off keeps its settings for later, and Remove timeline deletes them. A frame with a timeline exports over its own length.
Sprites export as a sprite sheet, a ZIP of frames, APNG, GIF, MP4 or WebM. See Exporting.