Wren a web browser where WebAssembly runs everything, JavaScript included

Wren 0.6.28

Wren 0.6.28 gives its scroll bars room as Chrome's, docks its developer tools, keeps frames and popups in the history, and runs pages that rebuild their DOM faster again.

This is still a beta, under development.

Highlights

  • Classic scroll bars: page and element scroll bars take their room, with arrows at their ends (documentElement.clientWidth is the window less the bar, as in Chrome on Windows); scrollbar-gutter and scrollbar-width apply. The old overlay bars are layout.scrollbar.overlay.
  • Developer tools you dock: drag a tab onto a panel or an edge to split, onto a strip to join it, out to float it; panes resize from a few em to nearly the whole room and fold; the layout is kept in the profile.
  • History through frames: back and forward walk the navigations made inside frames, a frame keeps the Window of its first blank document, and so does a window opened by window.open; anchor links and back within a page scroll as the HTML standard says; scroll anchoring keeps the view when content loads above it.
  • Faster pages that rebuild their DOM: one call into the browser makes a node, the collection skips wrappers that hold nothing, the interpreter calls getters itself (a page that rebuilds 10,000 nodes every frame, measured on one machine: about 142 -> 163 frames a second).
  • More of the web platform: ::backdrop, ::placeholder, scrollend, document.domain, CSP Embedded Enforcement, clip, CDATA sections, namespaced attributes, URLPattern and URL setters as the standards say, SharedArrayBuffer between a page and its workers.
  • Rendering fixes from real sites: table rows grow to their cells, an absolutely positioned child of a flex or grid container is aligned, margins collapse through empty boxes, form controls take their own line height, style sheets resolve URLs against the base URL, and hovering one link of a menu lights only that link.
  • Names and keywords are matched ASCII case-insensitively everywhere, as the web platform says (a Kelvin sign is not a K).
  • Menus are dense and scroll when the window is too low; a right click on a download opens its actions; Setup's status line no longer blinks.
  • Built with Odin dev-2026-11, the C runtime linked statically on Windows.

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