Cilk Plus Licensing

How is Intel Cilk Plus licensed?

Intel Cilk Plus is available under multiple licenses:

  • A commercial license
  • The version shipped in the "cilkplus" branch of the GCC C/C++ compiler is licensed under BSD license.
  • The sources of the Intel Cilk Plus runtime are made available under a BSD license. 

Regardless of how they are licensed, all of the versions of Intel Cilk Plus are built from the exact same code base.

Please pay close attention to the usage restrictions imposed by each license to make sure you are using the proper version.

Which license is right for my needs?

Intel Cilk Plus is available commercially as a binary distribution, and in open source in both source and binary forms.

If you need commercial support services you should purchase either a standalone commercial license or take advantage of the considerable value in purchasing the Intel® Parallel Studio or Intel® Compiler Professional Edition.

If your legal counsel is comfortable with your use of software under the BSD open source license and you do not require commercial support services, please download the latest version of open source Intel Cilk Plus.

What are the ramifications of multi-licensing?


Users of Intel Cilk Plus can get the same exact code as any Intel Cilk Plus commercial release (same code base, same binaries) under either the commercial or Open Source Software (OSS) license.

More frequent releases are available under the OSS license (stable releases, with source code and validated binaries; or development releases, with source code, but no binaries).

Commercial or OSS users of Intel Cilk Plus can use the contribution process to make changes to Intel Cilk Plus.