Which License is Right for Me?

Intel Cilk Plus is available under multiple licenses:

Commerial License

  • Intel Cilk Plus is implemented as part of the C/C++ compiler from the Intel® Parallel Studio XE suites.  Choose this if you require support from Intel or if you cannot accept the restrictions of the BSD license.

Open Source License

  • GCC 4.9 - ​Intel Cilk Plus is available in the "cilkplus" branch of the GCC 4.9 C and C++ compilers. The compiler portions are merged into the GCC sources.  A subset of Cilk Plus (minus cilk_for and ZCA annotations) has been merged into the mainline GCC 4.9 distribution. We expect to merge the missing features in in the future. The Cilk Plus runtime sources shipped with the GCC compiler is licensed under the BSD license. Choose this option if you wish to tinker with the generated code or runtime, or just want the source and can accept the restrictions of the BSD license.
  • GCC 4.8 - Intel Cilk Plus is available as a branch of GCC 4.8.  GCC 4.8 has recently shipped and this branch should be more stable than the 4.9 branch which is under active development.
  • Clang - Intel Cilk Plus is available in the Clang frontend of LLVM as a  project on Github

Intel Commercial Releases

The commercial version of Intel Cilk Plus is available from Intel in one of the Intel® Parallel Studio XE suites.

Visit our Software Evaluation Center to get a copy of these products.

If you are currently a student and not paid or compensated for software development, Intel® C++ Studio XE is available for free for academic use on Linux*, Windows* and OS X*.  See http://software.intel.com/en-us/intel-education-offerings and click in the "Student" tab for all the details.

Open Source Releases

​GCC Development Branch

Intel Cilk Plus has been integrated into the "cilkplus" branch of the GCC live-sources. The compiler and associated branches are available at http://gcc.gnu.org/svn/gcc/branches/cilkplus.

Detailed instructions are available at How to Download, Build, and Install Cilkplus GCC on Linux.

Questions, bug reports, or issues should be posted in the Intel Cilk Plus forum.  Rules for using the Cilk trademark are also available.

Cilk Plus/LLVM Development Branch

Intel Cilk Plus is available in the Clang frontend of LLVM as a project on Github. The compiler and associated branches are available from Github.  See the  Cilk Plus/LLVM page for information on how to download and build the compiler sources.

Questions, bug reports, or issues should be posted in the Intel Cilk Plus forum.  Rules for using the Cilk trademark are also available.

Cilk Plus runtime source

The Intel Cilk Plus run time library is being maintained via an upstream, BSD-licensed version. The source for the runtime can be downloaded from the Intel Cilk Plus Download page. This is the complete runtime source to support the Linux* and OS X* operating systems and has been tested on both the x86_32 and x86_64 architectures.

Please help port the Cilk Plus runtime to other architectures!

While there is very little architecture-specific code, be aware that access to shared variables currently assumes sequential consistency. Architectures using a different memory model may require the insertion of additional memory barriers.

Changes to the Intel Cilk Plus runtime are welcome!  Please see the Code Contribution page for information on contributing to this project.