Wormhole 1.0.0 · Release notes

Added

Blinking text (SGR 5 and 6) now blinks, fading once a second while the window is in front, and stays steady when Reduce Motion is on; overlined text (SGR 53) gets its line along the top of the cell, in the underline color when the program set one.
Programs can edit rectangles of the screen: fill (DECFRA), erase (DECERA, and DECSERA, which keeps protected cells), copy (DECCRA) and change or reverse attributes (DECCARA, DECRARA, with DECSACE choosing the stream of cells or the rectangle). They count from the scrolling region in origin mode and are cut to the screen.
A program can ask for the checksum of part of the screen (DECRQCRA), which test suites such as esctest2 read the screen back with. It is off: it also lets a program, over ssh too, read the screen cell by cell. Settings → Terminal → "Let programs read the screen back" (or allow_screen_checksum in config.json) turns it on for new terminals.
A program can move, resize, minimise, raise and full-screen the window and read its title back (xterm's window operations, CSI … t). It is off, because a title is text a program chose and reading it back types it into the next program: Settings → Terminal → "Let programs control the window" (or allow_window_ops in config.json) turns it on for new terminals. A size in rows and columns resizes the window so that the terminal that asked gets that size. Reports of the window's size and place are always answered.
Colors a program sets (OSC 4, 5, 10 to 19) also paint the pane's padding and are reset by OSC 104, 105 and 110 to 119; a # color is read as the X11 convention does (#3a7 is #3000a0007000).
Programs can switch to 8-bit controls (S8C1T) and set a conformance level (DECSCL), and reverse wraparound (modes 45 and 1045) works for backspace and cursor-left.
National replacement character sets (German, French, Swedish and the rest of the VT200 family, after CSI ? 42 h), the DEC Technical and DEC Supplemental sets and the ISO Latin-1 supplement can be designated and shifted into place (SCS, SO, SI, LS2, LS3, SS2, SS3). Shifting columns sideways (SL, SR), the DEC locator (DECELR, DECSLE, DECRQLP, DECEFR: the mouse answers as a locator when a program asks for it) and the state reports (DECRQPSR for the cursor and the tab stops, DECRQTSR, with DECRSPS and DECRSTS to put them back, DECRQDE) are understood too. The device attributes (DA1) now list exactly these and the rest of what the engine does.

Changed

Wormhole runs on its own terminal engine, written from the specifications, in place of alacritty's. It reads program output about three times as fast (2.85 times alacritty's core in the engine benchmark), and in our comparison of seven terminals on the same Mac the app is the fastest overall, six times as fast as Terminal.app. It passes every case of its own conformance suite, 544 of 567 esctest2 tests and every ucs-detect category, and adds what alacritty's core lacked: left and right margins (DECLRMM), selective erase, every DEC character set, setting and terminfo reports (DECRQSS, XTGETTCAP), and pictures that live in the grid, so kitty, Sixel and iTerm2 images scroll and reflow with the text.
Text is sized as Unicode 18 says, and the sizing matches ucs-detect's in every category. A conjunct of an Indic script or Khmer, a base with a spacing vowel sign (Bengali, Burmese, Javanese, Thai, Lao and more) and the Arabic number sign take the cells they are drawn in, and an emoji followed by the text selector (a watch or a heart with U+FE0E) steps back to one cell.
Grapheme clustering (mode 2027) is on from the start, as in Ghostty, and after a reset. Emoji sequences, flags and the scripts above are one character of their own width to the terminal without the program asking; a program that counts code points can turn it off with CSI ? 2027 l.

Fixed

The terminal list stays put: pinned terminals first, then the rest from first made to last, and nothing moves when you open a terminal, split a pane, change folder or change status; a band keeps its place while it has a terminal. The ⌘1–⌘9 numbers are dealt down the list and then stay with their terminal (a new terminal gets the next free one, whatever it sits), and are dealt again only when you pin, unpin, drag or close one. Rows now slide to their new place (not with Reduce Motion). Settings → Terminals & sidebar has Order (Stable or Classic) and ⌘1–⌘9 numbers (Stay with the terminal or Follow the list) to bring the old behaviour back.