The Julia Language
Julia is a high-level, high-performance dynamic language for technical computing. The main homepage for Julia can be found at julialang.org. This is the GitHub repository of Julia source code, including instructions for compiling and installing Julia, below.
- Homepage: https://julialang.org
- Binaries: https://julialang.org/downloads/
- Source code: https://github.com/JuliaLang/julia
- Documentation: https://docs.julialang.org/
- Packages: https://juliaobserver.com/
- Discussion forum: https://discourse.julialang.org
- Slack: https://julialang.slack.com (get an invite from https://slackinvite.julialang.org)
- Code coverage: https://coveralls.io/r/JuliaLang/julia
New developers may find the notes in CONTRIBUTING helpful to start contributing to the Julia codebase.
Currently Supported Platforms
|Operating System||Architecture||CI||Binaries||Support Level|
|macOS 10.8+||x86-64 (64-bit)||✓||✓||Tier 1|
|Windows 7+||x86-64 (64-bit)||✓||✓||Tier 1|
|i686 (32-bit)||✓||✓||Tier 1|
|FreeBSD 11.0+||x86-64 (64-bit)||✓||✓||Tier 1|
|Linux 2.6.18+||x86-64 (64-bit)||✓||✓||Tier 1|
|i686 (32-bit)||✓||✓||Tier 1|
|ARM v7 (32-bit)||✓||Tier 2|
|ARM v8 (64-bit)||Tier 3|
|x86-64 musl libc||Tier 3|
|PowerPC (64-bit)||Tier 4|
All systems marked with ✓ for CI are tested using continuous integration for every commit. Systems with ✓ for binaries have official binaries available on the downloads page and are tested regularly. The PTX backend is supported by the JuliaGPU organization and requires the CUDAnative.jl package.
Tier 1: Julia is guaranteed to build from source and pass all tests on these platforms when built with default options. Official binaries are available for releases and CI is run on every commit.
Tier 2: Julia is guaranteed to build from source using default build options, but may or may not pass all tests. Official binaries are available on a case-by-case basis.
Tier 3: Julia may or may not build. If it does, it is unlikely to pass tests.
Tier 4: Julia is known not to build.
It is possible that Julia will build and work on other platforms too, and we're always looking to improve our platform coverage. If you're using Julia on a platform not listed here, let us know!
Source Download and Compilation
First, make sure you have all the required dependencies installed. Then, acquire the source code by cloning the git repository:
git clone git://github.com/JuliaLang/julia.git
(If you are behind a firewall, you may need to use the
https protocol instead of the
git config --global url."https://".insteadOf git://
Be sure to also configure your system to use the appropriate proxy settings, e.g. by setting the
By default you will be building the latest unstable version of Julia. However, most users should use the most recent stable version of Julia, which is currently the
1.0 series of releases. You can get this version by changing to the Julia directory and running
git checkout v1.0.3
make to build the
julia executable. To perform a parallel build, use
make -j N and supply the maximum number of concurrent processes. (See Platform Specific Build Notes for details.)
When compiled the first time, it will automatically download and build its external dependencies.
This takes a while, but only has to be done once. If the defaults in the build do not work for you, and you need to set specific make parameters, you can save them in
Make.user, and place the file in the root of your Julia source. The build will automatically check for the existence of
Make.user and use it if it exists.
Building Julia requires 5GiB of disk space and approximately 2GiB of virtual memory.
You can create out-of-tree builds of Julia by specifying
make O=<build-directory> configure on the command line. This will create a directory mirror, with all of the necessary Makefiles to build Julia, in the specified directory. These builds will share the source files in Julia and
deps/srccache. Each out-of-tree build directory can have its own
Make.user file to override the global
Make.user file in the top-level folder.
If you need to build Julia on a machine without internet access, use
make -C deps getall to download all the necessary files. Then, copy the
julia directory over to the target environment and build with
Note: The build process will fail badly if any of the build directory's parent directories have spaces or other shell meta-characters such as
: in their names (this is due to a limitation in GNU make).
Once it is built, you can run the
julia executable after you enter your julia directory and run
To run julia from anywhere you can:
add an alias (in
echo "alias julia='/path/to/install/folder/bin/julia'" >> ~/.bashrc && source ~/.bashrc), or
add a soft link to the
juliaexecutable in the
/usr/local/bin(or any suitable directory already in your path), or
juliadirectory to your executable path for this shell session (in
export PATH="$(pwd):$PATH"; in
set path= ( $path $cwd )), or
juliadirectory to your executable path permanently (e.g. in
Make.userand then run
make install. If there is a version of Julia already installed in this folder, you should delete it before running
Now you should be able to run Julia like this:
If everything works correctly, you will see a Julia banner and an interactive prompt into which you can enter expressions for evaluation. (Errors related to libraries might be caused by old, incompatible libraries sitting around in your PATH. In this case, try moving the
julia directory earlier in the PATH). Note that most of the instructions above apply to unix systems.
Your first test of Julia determines whether your build is working properly. From the UNIX/Windows command prompt inside
julia source directory, type
make testall. You should see output that lists a series of running tests;
if they complete without error, you should be in good shape to start using Julia.
You can read about getting started in the manual.
If you are building a Julia package for distribution on Linux, macOS, or Windows, take a look at the detailed notes in DISTRIBUTING.md.
Updating an existing source tree
If you have previously downloaded
git clone, you can update the
existing source tree using
git pull rather than starting anew:
cd julia git pull && make
Assuming that you had made no changes to the source tree that will conflict with upstream updates, these commands will trigger a build to update to the latest version.
Over time, the base library may accumulate enough changes such that the bootstrapping process in building the system image will fail. If this happens, the build may fail with an error like
*** This error is usually fixed by running 'make clean'. If the error persists, try 'make cleanall' ***
As described, running
make clean && makeis usually sufficient. Occasionally, the stronger cleanup done by
make cleanallis needed.
New versions of external dependencies may be introduced which may occasionally cause conflicts with existing builds of older versions.
maketargets exist to help wipe the existing build of a dependency. For example,
make -C deps clean-llvmwill clean out the existing build of
llvmwill be rebuilt from the downloaded source distribution the next time
make -C deps distclean-llvmis a stronger wipe which will also delete the downloaded source distribution, ensuring that a fresh copy of the source distribution will be downloaded and that any new patches will be applied the next time
b. To delete existing binaries of
juliaand all its dependencies, delete the
./usrdirectory in the source tree.
If you've updated macOS recently, be sure to run
xcode-select --installto update the command line tools. Otherwise, you could run into errors for missing headers and libraries, such as
ld: library not found for -lcrt1.10.6.o.
If you've moved the source directory, you might get errors such as
CMake Error: The current CMakeCache.txt directory ... is different than the directory ... where CMakeCache.txt was created., in which case you may delete the offending dependency under
In extreme cases, you may wish to reset the source tree to a pristine state. The following git commands may be helpful:
git reset --hard #Forcibly remove any changes to any files under version control git clean -x -f -d #Forcibly remove any file or directory not under version control
To avoid losing work, make sure you know what these commands do before you run them.
gitwill not be able to undo these changes!
Julia does not install anything outside the directory it was cloned into. Julia can be completely uninstalled by deleting this directory. Julia packages are installed in
~/.julia by default, and can be uninstalled by deleting
Platform-Specific Build Notes
- GCC version 4.7 or later is required to build Julia.
- To use external shared libraries not in the system library search path, set
- Instead of setting
LDFLAGS, putting the library directory into the environment variable
LD_LIBRARY_PATH(at both compile and run time) also works.
- Instead of setting
USE_SYSTEM_*flags should be used with caution. These are meant only for troubleshooting, porting, and packaging, where package maintainers work closely with the Julia developers to make sure that Julia is built correctly. Production use cases should use the officially provided binaries. Issues arising from the use of these flags will generally not be accepted.
- See also the external dependencies.
Julia can be built for a non-generic architecture by configuring the
ARCH Makefile variable. See the appropriate section of
Make.inc for additional customization options, such as
For example, to build for Pentium 4, set
MARCH=pentium4 and install the necessary system libraries for linking. On Ubuntu, these may include lib32gfortran-6-dev, lib32gcc1, and lib32stdc++6, among others.
You can also set
MARCH=native for a maximum-performance build customized for the current machine CPU.
Linux Build Troubleshooting
|OpenBLAS build failure||Set one of the following build options in
If you get an error that looks like
|Illegal Instruction error||Check if your CPU supports AVX while your OS does not (e.g. through virtualization, as described in this issue).|
You need to have the current Xcode command line utilities installed: run
xcode-select --install in the terminal.
You will need to rerun this terminal command after each macOS update, otherwise you may run into errors involving missing libraries or headers.
You will also need a 64-bit gfortran to compile Julia dependencies. The gfortran-4.7 (and newer) compilers in Homebrew work for building Julia.
If you have set
DYLD_LIBRARY_PATH in your
.bashrc or equivalent, Julia may be unable to find various libraries that come bundled with it. These environment variables need to be unset for Julia to work.
Clang is the default compiler on FreeBSD 11.0-RELEASE and above.
The remaining build tools are available from the Ports Collection, and can be installed using
pkg install git gcc gmake cmake pkgconf.
To build Julia, simply run
gmake must be used rather than
make on FreeBSD corresponds to the incompatible BSD Make rather than GNU Make.)
As mentioned above, it is important to note that the
USE_SYSTEM_* flags should be used with caution on FreeBSD.
This is because many system libraries, and even libraries from the Ports Collection, link to the system's
or to another library which links to the system
This library declares its GCC version to be 4.6, which is too old to build Julia, and conflicts with other libraries when linking.
Thus it is highly recommended to simply allow Julia to build all of its dependencies.
If you do choose to use the
USE_SYSTEM_* flags, note that
/usr/local is not on the compiler path by default, so you may need
CPPFLAGS=-I/usr/local/include to your
Make.user, though doing so may interfere with
Note that the x86 architecture does not support threading due to lack of compiler runtime library support, so you may need to
JULIA_THREADS=0 in your
Make.user if you're on a 32-bit system.
In order to build Julia on Windows, see README.windows.
Julia can be developed in an isolated Vagrant environment. See the Vagrant README for details.
Required Build Tools and External Libraries
Building Julia requires that the following software be installed:
- GNU make — building dependencies.
- gcc & g++ (>= 4.7) or Clang (>= 3.1, Xcode 4.3.3 on macOS) — compiling and linking C, C++.
- libatomic — provided by gcc and needed to support atomic operations.
- python (>=2.7) — needed to build LLVM.
- gfortran — compiling and linking Fortran libraries.
- perl — preprocessing of header files of libraries.
- wget, curl, or fetch (FreeBSD) — to automatically download external libraries.
- m4 — needed to build GMP.
- awk — helper tool for Makefiles.
- patch — for modifying source code.
- cmake (>= 3.4.3) — needed to build
- pkg-config — needed to build
libgit2correctly, especially for proxy support.
On Debian-based distributions (e.g. Ubuntu), you can easily install them with
sudo apt-get install build-essential libatomic1 python gfortran perl wget m4 cmake pkg-config
Julia uses the following external libraries, which are automatically downloaded (or in a few cases, included in the Julia source repository) and then compiled from source the first time you run
- LLVM (6.0 + patches) — compiler infrastructure (see note below).
- FemtoLisp — packaged with Julia source, and used to implement the compiler front-end.
- libuv (custom fork) — portable, high-performance event-based I/O library.
- OpenLibm — portable libm library containing elementary math functions.
- DSFMT — fast Mersenne Twister pseudorandom number generator library.
- OpenBLAS — fast, open, and maintained basic linear algebra subprograms (BLAS) library, based on Kazushige Goto's famous GotoBLAS (see note below).
- LAPACK (>= 3.5) — library of linear algebra routines for solving systems of simultaneous linear equations, least-squares solutions of linear systems of equations, eigenvalue problems, and singular value problems.
- MKL (optional) – OpenBLAS and LAPACK may be replaced by Intel's MKL library.
- SuiteSparse (>= 4.1) — library of linear algebra routines for sparse matrices.
- PCRE (>= 10.00) — Perl-compatible regular expressions library.
- GMP (>= 5.0) — GNU multiple precision arithmetic library, needed for
- MPFR (>= 4.0) — GNU multiple precision floating point library, needed for arbitrary precision floating point (
- libgit2 (>= 0.23) — Git linkable library, used by Julia's package manager.
- curl (>= 7.50) — libcurl provides download and proxy support for Julia's package manager.
- libssh2 (>= 1.7) — library for SSH transport, used by libgit2 for packages with SSH remotes.
- mbedtls (>= 2.2) — library used for cryptography and transport layer security, used by libssh2
- utf8proc (>= 2.1) — a library for processing UTF-8 encoded Unicode strings.
- libosxunwind — clone of libunwind, a library that determines the call-chain of a program.
Notes for distribution package maintainers
We understand that package maintainers will typically want to make use of system libraries where possible. Please refer to the above version requirements and additional notes below. It is strongly advised that package maintainers apply the patches included in the Julia repo for LLVM and other libraries, should they choose to use SYSTEM versions. A list of maintained Julia packages for various platforms is available at https://julialang.org/downloads/platform.html.
System Provided Libraries
If you already have one or more of these packages installed on your system, you can prevent Julia from compiling duplicates of these libraries by passing
make or adding the line to
Make.user. The complete list of possible flags can be found in
Please be aware that this procedure is not officially supported, as it introduces additional variability into the installation and versioning of the dependencies, and is recommended only for system package maintainers. Unexpected compile errors may result, as the build system will do no further checking to ensure the proper packages are installed.
The most complicated dependency is LLVM, for which we require additional patches from upstream (LLVM is not backward compatible).
For packaging Julia with LLVM, we recommend either:
- bundling a Julia-only LLVM library inside the Julia package, or
- adding the patches to the LLVM package of the distribution.
- A complete list of patches is available in
deps/llvm.mk, and the patches themselves are in
- The only Julia-specific patch is the lib renaming (
llvm-symver-jlprefix.patch), which should not be applied to a system LLVM.
- The remaining patches are all upstream bug fixes, and have been contributed into upstream LLVM.
- A complete list of patches is available in
Using an unpatched or different version of LLVM will result in errors and/or poor performance. Though Julia can be built with newer LLVM versions, support for this should be regarded as experimental and not suitable for packaging.
Julia uses a custom fork of libuv. It is a small dependency, and can be safely bundled in the same package as Julia, and will not conflict with the system library. Julia builds should not try to use the system libuv.
BLAS and LAPACK
As a high-performance numerical language, Julia should be linked to a multi-threaded BLAS and LAPACK, such as OpenBLAS or ATLAS, which will provide much better performance than the reference
libblas implementations which may be default on some systems.
For a 64-bit architecture, the environment should be set up as follows:
# bash source /path/to/intel/bin/compilervars.sh intel64
Add the following to the
USE_INTEL_MKL = 1
It is highly recommended to start with a fresh clone of the Julia repository.
Source Code Organization
The Julia source code is organized as follows:
base/ source code for the Base module (part of Julia's standard library) stdlib/ source code for other standard library packages contrib/ editor support for Julia source, miscellaneous scripts deps/ external dependencies doc/src/manual source for the user manual doc/src/stdlib source for standard library function reference src/ source for Julia language core test/ test suites ui/ source for various front ends usr/ binaries and shared libraries loaded by Julia's standard libraries
If you would rather not compile the latest Julia from source, platform-specific tarballs with pre-compiled binaries are also available for download.
You can either run the
julia executable using its full path in the directory created above, or add that directory to your executable path so that you can run the Julia program from anywhere (in the current shell session):
Now you should be able to run Julia like this:
On Windows, double-click
If everything works correctly, you will see a Julia banner and an interactive prompt into which you can enter expressions for evaluation. You can read about getting started in the manual.
Note: Although some system package managers provide Julia, such installations are neither maintained nor endorsed by the Julia project. They may be outdated and/or unmaintained. We recommend you use the official Julia binaries instead.
Editor and Terminal Setup
Currently, Julia editing mode support is available for a number of
editors. While Julia modes for
Sublime Text, and
Vim have their own repos,
others such as Textmate, Notepad++, and Kate, are in
In the terminal, Julia makes great use of both control-key and meta-key bindings. To make the meta-key bindings more accessible, many terminal emulator programs (e.g.,
xterm, etc.) allow you to use the alt or option key as meta. See the section in the manual on the Julia REPL for more details.