To gather community feedback, the provisional specification for SYCL 1.2 has been released by The Khronos Group. SYCL extends itself upon OpenCL with the C++11 standard. This technology is built on another Khronos platform, SPIR, which allows the OpenCL C programming language to be mapped onto LLVM, with its hundreds of compatible languages (and Khronos is careful to note that they intend for anyone to make their own compatible alternative langauge).
In short, SPIR allows many languages which can compile into LLVM to take advantage of OpenCL. SYCL is the specification for creating C++11 libraries and compilers through SPIR.
As stated earlier, Khronos wants anyone to make their own compatible language:
While SYCL is one possible solution for developers, the OpenCL group encourages innovation in programming models for heterogeneous systems, either by building on top of the SPIR™ low-level intermediate representation, leveraging C++ programming techniques through SYCL, using the open source CLU libraries for prototyping, or by developing their own techniques.
SYCL 1.2 supports OpenCL 1.2 and they intend to develop it alongside OpenCL. Future releases are expected to support the latest OpenCL 2.0 specification and keep up with future developments.
The SYCL 1.2 provisional spec is available at the Khronos website.