RV8

A standalone browser-engine repo for Soliloquy, combining Servo rendering with V8 JavaScript execution.

Related repos

Repo	Role
this repo (atechnology-company/rv8)	Canonical browser engine: multi-process IPC, Servo embed, V8, storage, viewportd
atechnology-company/soliloquy	Appliance runtime; in-tree src/rv8 stays aligned with this repo

Archived experiments (read-only, not maintained): atechnology-company/rover (single-process engine + rover-proto contracts) and atechnology-company/rover-desktop (thin Xilem shell). Their useful ideas—stable host service traits and DocumentSnapshot—are already covered here by ipc/messages.rs plus richer process/storage/Servo paths. Do not confuse those repos with the unrelated macOS launcher at semitechnological/rover.

Architecture

RV8 uses a Chrome-like multi-process architecture:

┌─────────────────────────────────────────────────────────┐
│                   Browser Process                       │
│  • Tab Management    • Navigation    • Process Control  │
├─────────────────────────────────────────────────────────┤
│                    IPC Channels                         │
├─────────────────────────────────────────────────────────┤
│  ┌──────────────────┐  ┌──────────────────────────────┐│
│  │ Renderer Process │  │           GPU Process        ││
│  │ (per tab)        │  │         (Compositor)         ││
│  │ • HTML/CSS Parse │  │  • Layer Compositing         ││
│  │ • Layout         │  │  • Hardware Acceleration     ││
│  │ • V8 JavaScript  │  └──────────────────────────────┘│
│  └──────────────────┘                                   │
│  ┌──────────────────────────────────────────────────┐  │
│  │              Network Process                      │  │
│  │         • HTTP/HTTPS • Caching • Cookies          │  │
│  └──────────────────────────────────────────────────┘  │
└─────────────────────────────────────────────────────────┘

Features

• V8 JavaScript Engine: TurboFan + Sparkplug compilation
• Servo Rendering: WebRender-based GPU rendering
• Chrome-like Optimizations: Tab discarding, prefetching, code caching
• Multi-Process: Sandboxed renderers, site isolation
• Modern Standards: HTTP/3, Web APIs, DevTools Protocol

viewportd (host embed protocol)

GPUI shells (e.g. mono-browser) spawn viewportd as a subprocess to avoid linking Servo into the UI crate.

cargo build -p rv8 --bin viewportd
RV8_VIEWPORT_WIDTH=1280 RV8_VIEWPORT_HEIGHT=800 ./target/debug/viewportd

Stdin (line-based):

Command	Example
Navigate	NAV https://example.com/
Resize	SIZE 1280 800
Scroll	SCROLL 0.0 120.0 (device pixels; positive y reveals content below)
Quit	QUIT

Stdout: RV8M metadata frames (title/url), then RV8F length-prefixed RGBA frames. See src/bin/viewportd.rs and servo_embed/viewport.rs.

Product-side clients should stay thin (mono-adapters); engine behavior and polyfills belong here in servo_embed/.

Quick Start

# Build
cargo build

# Run
cargo run -- https://example.com

# Run with single-process (debugging)
cargo run --features single-process -- https://example.com

Structure

.
├── lib.rs              # Library entry
├── main.rs             # Binary entry (multi-process)
├── core/               # Browser process
│   ├── browser.rs      # Main browser coordinator
│   ├── tab.rs          # Tab management
│   ├── config.rs       # Configuration
│   └── process_manager.rs # Child process spawning
├── renderer/           # Renderer process (Servo-based)
├── js/                 # JavaScript engine (V8)
├── compositor/         # GPU compositing
├── networking/         # Network stack
├── storage/            # sled persistence (cookies, session, profile)
├── ipc/                # Inter-process communication
└── optimizations/      # Performance tuning
    ├── flags.rs        # Chrome-like optimization flags
    ├── monitor.rs      # Performance monitoring
    └── preload.rs      # Resource prefetching

Storage

Persistent browser state lives under the profile directory in storage.sled (sled-backed). Incognito mode uses in-memory stores only.

Subsystem	Module	Notes
Profile metadata	storage/profile.rs	Profile id and meta tree
Cookies	storage/cookie.rs	CookieJar with insert/get/replace
Session	storage/session.rs	Tab snapshots per profile

Profile paths are defined in core/config.rs (BrowserDataDirs); see AGENTS.md for env vars and defaults.

use rv8::StorageManager;
use std::path::Path;

let storage = StorageManager::open(Path::new("/var/lib/soliloquy/browser/profiles/default"), false)?;
storage.cookies.insert(cookie)?;
storage.flush().await;

Cross-device sync and product adapters belong in mono (mono-adapters, feature rv8), not in this engine repo.

Integrates with the Plates ecosystem (optional)

4 different views

• Arc
• Chrome/Standard
• Minimal
• and our own take on the browser