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.
Visit the Servo Project page for news and guides.
Setting up your environment
Building servo requires rustup, version 1.8.0 or more recent.
If you have an older version, run
rustup self update.
To install on Windows, download and run
then follow the onscreen instructions.
To install on other systems, run:
curl https://sh.rustup.rs -sSf | sh
This will also download the current stable version of Rust, which Servo won’t use. To skip that step, run instead:
curl https://sh.rustup.rs -sSf | sh -s -- --default-toolchain none
See also Other installation methods
Please select your operating system:
Xcode version 10.2 or above is recommended.
On macOS(Intel based or ARM based) (Homebrew)
NOTE: run these steps after you've cloned the project locally.
cd servo brew bundle install --file=etc/taskcluster/macos/Brewfile brew bundle install --file=etc/taskcluster/macos/Brewfile-build pip install virtualenv
On Debian-based Linuxes
sudo apt install python3-virtualenv python3-pip ./mach bootstrap
./mach bootstrap doesn't work, file a bug, and, run the commands below:
sudo apt install git curl autoconf libx11-dev libfreetype6-dev libgl1-mesa-dri \ libglib2.0-dev xorg-dev gperf g++ build-essential cmake libssl-dev \ liblzma-dev libxmu6 libxmu-dev \ libxcb-render0-dev libxcb-shape0-dev libxcb-xfixes0-dev \ libgles2-mesa-dev libegl1-mesa-dev libdbus-1-dev libharfbuzz-dev ccache \ clang libunwind-dev libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev \ libgstreamer-plugins-bad1.0-dev autoconf2.13 llvm-dev
Additionally, you'll need a local copy of GStreamer with a version later than 16.2. You can place it in
support/linux/gstreamer/gst, or run
./mach bootstrap-gstreamer to set it up. On Ubuntu 20.04LTS, you can use the system GStreamer if you install the necessary packages:
sudo apt install gstreamer1.0-nice gstreamer1.0-plugins-bad
If you are using Ubuntu 16.04 or Linux Mint 18.* run
export HARFBUZZ_SYS_NO_PKG_CONFIG=1 before building to avoid an error with harfbuzz.
If you get an undefined symbol error on
gst_player_get_config try removing
gir1.2-gst-plugins-bad-1.0 and all old versions of clang, see #22016
sudo dnf install python3 python3-virtualenv python3-pip python3-devel python3 ./mach bootstrap
python3 ./mach bootstrap doesn't work, file a bug, and, run the commands below:
sudo dnf install curl libtool gcc-c++ libXi-devel libunwind-devel \ freetype-devel mesa-libGL-devel mesa-libEGL-devel glib2-devel libX11-devel \ libXrandr-devel gperf fontconfig-devel cabextract ttmkfdir expat-devel \ rpm-build openssl-devel cmake libX11-devel libXcursor-devel \ libXmu-devel dbus-devel ncurses-devel harfbuzz-devel \ ccache clang clang-libs python3-devel gstreamer1-devel \ gstreamer1-plugins-base-devel gstreamer1-plugins-bad-free-devel autoconf213
sudo yum install python-virtualenv python-pip ./mach bootstrap
./mach bootstrap doesn't work, file a bug, and, run the commands below:
sudo yum install curl libtool gcc-c++ libXi-devel freetype-devel \ mesa-libGL-devel mesa-libEGL-devel glib2-devel libX11-devel libXrandr-devel \ gperf fontconfig-devel cabextract ttmkfdir python expat-devel rpm-build \ openssl-devel cmake3 libXcursor-devel libXmu-devel \ dbus-devel ncurses-devel python34 harfbuzz-devel \ ccache clang clang-libs llvm-toolset-7
scl enable devtoolset-7 llvm-toolset-7 bash
with the following environmental variables set:
export CMAKE=cmake3 export LIBCLANG_PATH=/opt/rh/llvm-toolset-7/root/usr/lib64
On openSUSE Linux
sudo zypper install libX11-devel libexpat-devel Mesa-libEGL-devel Mesa-libGL-devel cabextract cmake \ dbus-1-devel fontconfig-devel freetype-devel gcc-c++ git glib2-devel gperf \ harfbuzz-devel libXcursor-devel libXi-devel libXmu-devel libXrandr-devel libopenssl-devel \ python3-pip python3-virtualenv rpm-build ccache llvm-clang libclang autoconf213 gstreamer-devel \ gstreamer-plugins-base-devel gstreamer-plugins-bad-devel
On Arch Linux
sudo pacman -S --needed base-devel git python python-virtualenv python-pip mesa cmake libxmu \ pkg-config ttf-fira-sans harfbuzz ccache llvm clang autoconf2.13 gstreamer gstreamer-vaapi \ gst-plugins-base gst-plugins-good gst-plugins-bad
On Gentoo Linux
sudo emerge net-misc/curl \ media-libs/freetype media-libs/mesa dev-util/gperf \ dev-python/virtualenv dev-python/pip dev-libs/openssl \ media-libs/harfbuzz dev-util/ccache sys-libs/libunwind \ x11-libs/libXmu x11-base/xorg-server sys-devel/clang \ media-libs/gstreamer media-libs/gst-plugins-bad media-libs/gst-plugins-base
With the following environment variable set:
export LIBCLANG_PATH=$(llvm-config --prefix)/lib64
On nixOS Linux
You will need to run this in every shell before running mach.
On Windows (MSVC)
You will also need to set the
PYTHON3 environment variable, e.g., to 'C:\Python39\python.exe' by doing:
setx PYTHON3 "C:\Python39\python.exe" /m
/m will set it system-wide for all future command windows.
- Install virtualenv.
In a normal Windows Shell (cmd.exe or "Command Prompt" from the start menu), do:
pip install virtualenv
If this does not work, you may need to reboot for the changed PATH settings (by the python installer) to take effect.
- Install the most recent GStreamer MSVC packages. You need to download the two
.msifiles for your platform from the GStreamer website and install them. The currently recommended version is 1.16.0. i.e.:
Note that the MinGW binaries will not work, so make sure that you install the MSVC the ones.
Note that you should ensure that all components are installed from gstreamer, as we require many of the optional libraries that are not installed by default.
Install Git for Windows (https://git-scm.com/download/win). DO allow it to add git.exe to the PATH (default settings for the installer are fine).
Install Visual Studio Community 2017 (https://www.visualstudio.com/vs/community/). You MUST add "Visual C++" to the list of installed components as well as the "Windows Universal C runtime." They are not on by default. Visual Studio 2017 MUST installed to the default location or mach.bat will not find it.
Note that version is hard to download online and is easier to install via Chocolatey with:
choco install -y visualstudio2017community --package-parameters="'--add Microsoft.VisualStudio.Component.Git'" Update-SessionEnvironment #refreshing env due to Git install #--- UWP Workload and installing Windows Template Studio --- choco install -y visualstudio2017-workload-nativedesktop
[Optional] Install LLVM for faster link times
You may experience much faster builds on Windows by following these steps. (Related Rust issue: https://github.com/rust-lang/rust/issues/37543)
- Download the latest version of LLVM (https://releases.llvm.org/).
- Run the installer and choose to add LLVM to the system PATH.
- Add the following to your Cargo config (Found at
%USERPROFILE%\.cargo\config). You may need to change the triple to match your environment.
[target.x86_64-pc-windows-msvc] linker = "lld-link.exe"
Troubleshooting a Windows environment
If you encountered errors with the environment above, do the following for a workaround:
- Download and install Build Tools for Visual Studio 2017
mach.bat build -d.
If you have troubles with
x64 typeprompt as
mach.batset by default:
- You may need to choose and launch the type manually, such as
x86_x64 Cross Tools Command Prompt for VS 2017in the Windows menu.)
python mach build -d
If you got the error
Cannot run mach in a path on a case-sensitive file system on Windows:
- Open Command Prompt or PowerShell as administrator.
- Disable case-sensitive for servo path,
fsutil.exe file SetCaseSensitiveInfo X:\path\to\servo disable
If you got the error
not found!then set the
WindowsSdkDirenvironment variable to an appropriate
Windows Kitdirectory containing
Redist\ucrt\DLLs\x64\api-ms-win-crt-runtime-l1-1-0.dll, for example
C:\Program Files (x86)\Windows Kits\10.
If you get the error
thread 'main' panicked at 'Unable to find libclang: "couldn\'t find any valid shared libraries matching: [\'clang.dll\', \'libclang.dll\'], set theLIBCLANG_PATH
environment variable to a path where one of these files can be found (invalid: ... invalid DLL (64-bit))])"'then
rustupmay have installed the 32-bit default target rather than the 64-bit one. You can find the configuration with
rustup show, and set the default with
rustup set default-host x86_64-pc-windows-msvc.
Cross-compilation for Android
./mach bootstrap-android --build to get Android-specific tools. See wiki for
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
Servo is built with Cargo, the Rust package manager. We also use Mozilla's Mach tools to orchestrate the build and other tasks.
To build Servo in development mode. This is useful for development, but the resulting binary is very slow.
git clone https://github.com/servo/servo cd servo ./mach build --dev ./mach run tests/html/about-mozilla.html
Or on Windows MSVC, in a normal Command Prompt (cmd.exe):
git clone https://github.com/servo/servo cd servo mach.bat build --dev
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
mach build will build both
libsimpleservo. To make compilation a bit faster, it's possible to only compile the servo binary:
./mach build --dev -p servo.
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:
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
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
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
-p INTERVALturns on the profiler and dumps info to the console every
-s SIZEsets the tile size for painting; defaults to 512
-zdisables all graphical output; useful for running JS / layout tests
-Z helpdisplays useful output to debug servo
Lopens URL prompt (
Rreloads current page (
-zooms out (
=zooms in (
left arrowgoes backwards in the history (
left arrowon Mac)
right arrowgoes forwards in the history (
right arrowon Mac)
Qexits Servo (
There are lots of mach commands you can use. You can list them with
The generated documentation can be found on https://doc.servo.org/servo/index.html