The Servo Parallel Browser Engine Project

Servo is a prototype web browser engine written in the Rust language. It is currently developed on 64-bit macOS, 64-bit Linux, 64-bit Windows, and Android.

Servo welcomes contribution from everyone. See CONTRIBUTING.md and HACKING_QUICKSTART.md for help getting started.

Visit the Servo Project page for news and guides.

Build Setup

• macOS
• Linux
• Windows
• Android

If these instructions fail or you would like to install dependencies manually, try the manual build setup.

macOS

• Ensure that the version showed by python --version is >= 3.10:
• Install Xcode
• Install Homebrew
• Run curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
• Run ./mach bootstrap
  Note: This will install the recommended version of GStreamer globally on your system.

Linux

• Run curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | sh
• Install Python (version >= 3.10):
  • Debian-like: Run sudo apt install python3-pip python3-venv
  • Fedora: Run sudo dnf install python3 python3-pip python3-devel
  • Arch: Run sudo pacman -S --needed python python-pip
  • Gentoo: Run sudo emerge dev-python/pip
• Run ./mach bootstrap

Windows

• Download and run rustup-init.exe then follow the onscreen instructions.
• Install chocolatey
• Install Python 3.11
• Run mach bootstrap
• This will install CMake, Git, Ninja, and the Visual Studio 2019 Build Tools via choco in an Administrator console. It can take quite a while.
• If you already have Visual Studio 2019 installed, this may not install all necessary components. Please follow the Visual Studio 2019 installation instructions in the manual setup.
• Run refreshenv

See also Windows Troubleshooting Tips.

Cloning the Repo

Your CARGO_HOME needs to point to (or be in) the same drive as your Servo repository (See #28530).

git clone https://github.com/servo/servo
cd servo

Building

Servo is built with Cargo, the Rust package manager. We also use Mozilla's Mach tools to orchestrate the build and other tasks. You can call Mach like this:

On Unix systems:

./mach [command] [arguments]

On Windows Commandline:

mach.bat [command] [arguments]

The examples below will use Unix, but the same applies to Windows.

The Rust compiler

Servo's build system uses rustup.rs to automatically download a Rust compiler. This is a specific version of Rust Nightly determined by the rust-toolchain.toml file.

Normal build

To build Servo in development mode. This is useful for development, but the resulting binary is very slow:

./mach build --dev
./mach run tests/html/about-mozilla.html

Release build

For benchmarking, performance testing, or real-world use. Add the --release flag to create an optimized build:

./mach build --release
./mach run --release tests/html/about-mozilla.html

Checking for build errors, without building

If you’re making changes to one crate that cause build errors in another crate, consider this instead of a full build:

./mach check

It will run cargo check, which runs the analysis phase of the compiler (and so shows build errors if any) but skips the code generation phase. This can be a lot faster than a full build, though of course it doesn’t produce a binary you can run.

Building for Android target

Prerequisites: Servo's build system assumes that both the Android SDK & NDK are already installed and expects the paths to be specified via the environment variables ANDROID_SDK_ROOT and ANDROID_NDK_ROOT.

Servo also expects the following components are installed via sdkmanager:

For building:

sdkmanager install platform-tools platforms;android-33

To run in emulator, also install the related components:

sdkmanager install emulator system-images;android-33;google_apis;x86

Build commands: For ARM (armv7-linux-androideabi, most phones):

./mach build --release --android
./mach package --release --android

For x86 (typically for the emulator):

./mach build --release --target i686-linux-android
./mach package --release --target i686-linux-android

Install the APK to the device or emulator:

./mach install --release --android

Running

Run Servo with the command:

./servo [url] [arguments] # if you run with nightly build
./mach run [url] [arguments] # if you run with mach

# For example
./mach run https://www.google.com

Commandline Arguments

• -p INTERVAL turns on the profiler and dumps info to the console every INTERVAL seconds
• -s SIZE sets the tile size for painting; defaults to 512
• -z disables all graphical output; useful for running JS / layout tests
• -Z help displays useful output to debug servo

Keyboard Shortcuts

• Ctrl+L opens URL prompt (Cmd+L on Mac)
• Ctrl+R reloads current page (Cmd+R on Mac)
• Ctrl+- zooms out (Cmd+- on Mac)
• Ctrl+= zooms in (Cmd+= on Mac)
• Alt+left arrow goes backwards in the history (Cmd+left arrow on Mac)
• Alt+right arrow goes forwards in the history (Cmd+right arrow on Mac)
• Esc or Ctrl+Q exits Servo (Cmd+Q on Mac)

Runtime dependencies

Linux

• GStreamer >=1.16
• gst-plugins-bad >=1.16
• libXcursor
• libXrandr
• libXi
• libxkbcommon
• vulkan-loader

Developing

There are lots of mach commands you can use. You can list them with ./mach --help.

The generated documentation can be found on https://doc.servo.org/servo/index.html