RAJA is a collection of C++ software abstractions, being developed at Lawrence Livermore National Laboratory (LLNL), that enable architecture portability for HPC applications. The overarching goals of RAJA are to:
- Make existing (production) applications portable with minimal disruption
- Provide a model for new applications so that they are portable from inception.
RAJA uses standard C++11 -- C++ is the predominant programming language in which many LLNL codes are written. RAJA is rooted in a perspective based on substantial experience working on production mesh-based multiphysics applications at LLNL. Another goal of RAJA is to enable application developers to adapt RAJA concepts and specialize them for different code implementation patterns and C++ usage, since data structures and algorithms vary widely across applications.
RAJA shares goals and concepts found in other C++ portability abstraction approaches, such as Kokkos and Thrust. However, it includes concepts that are absent in other models and which are fundamental to LLNL codes.
It is important to note that RAJA is very much a work-in-progress. The community of researchers and application developers at LLNL that are actively contributing to it and developing new capabilities is growing. The publicly-released version contains only core pieces of RAJA as they exist today. While the basic interfaces are fairly stable, the implementation of the underlying concepts is being refined. Additional features will appear in future releases.
The RAJA code lives in a GitHub repository. To clone the repo, use the command:
git clone https://github.com/llnl/raja.git
Then, you can build RAJA like any other CMake project, provided you have a C++ compiler that supports the C++11 standard. The simplest way to build the code is to do the following in the top-level RAJA directory (in-source builds are not allowed!):
mkdir build cd build cmake ../ make
More details about RAJA configuration options are located in the User Documentation.
The RAJA-examples repository contains three proxy applications that use the RAJA
programming model. These applications can be built along with the rest of the
RAJA framework by setting
-DRAJA_ENABLE_APPLICATIONS=On when running CMake.
When this option is passed to CMake, the RAJA-examples repository is cloned using
git to the directory
extra/llnl-raja-proxies in the project root. The example applications will be built using the same configuration that the RAJA library uses.
The Documentation is the best place to start learning about RAJA.
Other references that may be of interest include:
- The RAJA Portability Layer: Overview and Status (2014)
- RAJA Overview (extracted from ASC Tri-lab Co-design Level 2 Milestone Report 2015)
To cite RAJA, please use the following reference:
- R. D. Hornung and J. A. Keasler, The RAJA Poratability Layer: Overview and Status, Tech Report, LLNL-TR-661403, Sep. 2014.
Interested in keep up with RAJA or communicating with its developers and users? Please join our mailing list over at Google Groups:
If you have questions, find a bug, or have ideas about expanding the functionality or applicability of RAJA and are interested in contributing to its development, please do not hesitate to contact us. We are very interested in improving RAJA and exploring new ways to use it.
The RAJA team follows the GitFlow development model. Folks wishing to contribute to RAJA, should
include their work in a feature branch created from the RAJA
Then, create a pull request with the
develop branch as the destination. That
branch contains the latest work in RAJA. Periodically, we will merge the
develop branch into the
master branch and tag a new release.
The original developers of RAJA are:
- David Beckingsale (email@example.com)
- Jason Burmark (firstname.lastname@example.org)
- Holger Jones (email@example.com)
- Will Killian (firstname.lastname@example.org)
- Adam Kunen (email@example.com)
- Olga Pearce (firstname.lastname@example.org)
- David Poliakoff (email@example.com)
- Tom Scogland (firstname.lastname@example.org)
Copyright (c) 2016, Lawrence Livermore National Security, LLC.
Produced at the Lawrence Livermore National Laboratory.
All rights reserved.
Unlimited Open Source - BSD Distribution
For release details and restrictions, please read the LICENSE.txt file. It is also linked here: