mgbrowser v0.9.24 Experimental Preview

mgbrowser v0.9.24 Experimental Preview

Full 6-panel Chromium-style DevTools workspace (Elements, Console, Sources,
Network, Performance, Application) with Right/Bottom docking, draggable
splitter resize, interactive Element Picker (↖ / Ctrl+Shift+C) with 4-layer
Stylo box-model overlays, live element.style DOM/CSS editing, isolated Boa
worker JS Console REPL + Command Line API, and 4-tab Network request inspection.
Exact-source publication and public-install receipts are recorded in the dated
work log.

Linux x86_64 / X11 or XWayland, glibc 2.35 or newer. Rust 1.91.1, locked
dependencies and pure-Rust implementation backends.

Six-Panel Chromium-Style DevTools Workspace

mg-chassis, mg-sparkle and mg-browser expand the built-in DevTools panel
(F12 / Ctrl+Shift+I / right-click Inspect) across six panels with
Right/Bottom docking (⬓ / ◨), a draggable 4 px splitter, and compact-overlay
fallback on narrow viewports:

• Interactive Element Picker (↖ / Ctrl+Shift+C) & 4-Layer Box Model
  Overlay: hovering the page highlights any DOM element with concentric Stylo
  Margin (orange), Border (yellow), Padding (green), and Content (blue) layers
  plus a floating tag#id.class W×H tooltip; clicking selects the element as
  $0 in Elements without activating page links or forms.
• Elements (Styles | Computed | Box Model): collapsible ▸/▾ DOM
  tree with == $0 badge, CSS selector & text search (Ctrl+F), H visibility
  toggle, Delete node removal, live editable element.style { ... } inline
  declarations with instant Stylo restyle/reflow and color swatches, real Stylo
  ComputedStyle properties, and a concentric 4-layer Box Model diagram.
• Console (Ctrl+Shift+J): 19-method WHATWG/Chromium console.* API
  (log, info, warn, error, debug, dir, dirxml, table, trace,
  assert, clear, count, countReset, group, groupCollapsed,
  groupEnd, time, timeLog, timeEnd) with %s/%d/%i/%f/%o/%O/%j/%c/%%
  formatting inside the isolated Boa worker without invoking user JS getters or
  Proxy traps; interactive > JS REPL with Command Line API ($_, $0..$4,
  $(), $$(), keys(), values(), dir(), dirxml(), table(), clear(),
  copy(), inspect()), on-demand isolated worker startup on static/oversize
  pages, inline ▶/▼ object & DOM property tree expansion, [Inspect]
  jump-to-Elements badges, Tab ghost autocomplete, 64-entry Up/Down
  history, Shift+Enter multiline input, -term negative text filtering,
  severity pills, and Preserve log.
• Sources: navigator for [HTML] document source, [CSS] inline and
  same-origin stylesheets, and [JS] inline and external scripts with
  line-numbered syntax-colored viewing and Ctrl+F line search.
• Network (Ctrl+Shift+E): All/Doc/CSS/JS/Font/Img filters,
  URL substring filter, Preserve log, Disable cache, Waterfall timeline with
  DOMContentLoaded (blue) and Load (red) vertical markers, and a 4-tab
  Request Inspector drawer (Headers | Response | Preview | Timing) that
  redacts sensitive cookie, set-cookie, and authorization header values.
• Performance (Ctrl+Shift+P): ● Reload & Profile, Load Phase Flame Bar,
  64-frame render-duration sparkline with 16.7 ms (60 FPS) budget line, Boa
  worker opcode/allocation metrics, and frame/style/shaping cache hit telemetry.
• Application: live session Cookies table (with redacted byte lengths and
  Clear Cookies), Security origin/TLS/worker-sandbox summary, and Resources
  inventory.

Validation status

Workspace debug and release unit/integration tests (including legacy-test-engine
and protocol v8 worker session selftests), component boundary and no-chrome
embedding checks, packaged native X11 inspector-smoke across light/dark and
100%/200% scale, all 13 native/CDP smoke helpers, all 8 frozen JSPLAN gates, and
both complete reviewed WPT lanes pass.

Install and known limitations

curl -fsSL https://mgbrowser.org/install.sh | bash

The installer follows the latest published release and verifies SHA-256 before
installing without sudo. Checksums are not independent signatures. Existing
processes must restart to use an installed update.

Modern-web compatibility is poor. The Google search to first result journey is
not working. Real Reddit loading and full interactive Google News features
remain unfinished goals. Ordinary Playwright is unsupported: autoattachment,
debugger waiting/resume, downloads, utility worlds, promise awaiting and stock
locator message-size policy remain open. JavaScript breakpoint stepping, heap
snapshots, flamechart CPU sampling, and persistent Web Storage (localStorage /
IndexedDB) remain outside this bounded DevTools increment.

Boa JavaScript is enabled by default (--disable-scripts opts out); documents
exceeding the 1 MiB source or 2 MiB wire admission cap skip page-load script
execution and spawn a bounded on-demand worker only when interactive Console
evaluation is explicitly requested. Full CSS/CSSOM, intrinsic sizing, baselines,
bidi and floats remain incomplete. This increment does not complete F-011/F-016/
F-024/F-025/F-026/F-027 or formal MVP.

Linux X11/XWayland is the supported GUI target. The restricted JavaScript worker
is not a sandbox for the browser as a whole. Do not use this preview for banking,
sensitive authenticated browsing or arbitrary hostile websites. Project code,
documentation and original artwork use Apache-2.0. Dependencies retain their
licenses in packaged THIRD_PARTY_LICENSES.txt. Old tags/assets stay immutable.