Intel recently released their own High Level Synthesis compiler for Quartus; like HLx, it's free and you can use it now on whatever device you want. You still h

Intel recently released their own High Level Synthesis compiler for Quartus; like HLx, it's free and you can use it now on whatever device you want. You still have to do the interconnection to the CPU, if you have one. Unlike Xilinx, though, Intel (very very recently) just started offering their OpenCL-for-FPGA SDK for free, and it works on most of their device families, including Arria/Xeon and Cyclone/ARM. I always found it disappointing that the OpenCL SDKs were normally licensed, since they're more-or-less a logical extension of HLS support. So that's nice of Intel. They don't have any equivalent to Xilinx SDSoC though, but for datacenter targets they're shipping a different set of SDKs anyway (called "OPAE"), so maybe in the future they'll build something on top of the OPAE and OpenCL support (e.g. single-source model, like Sycl)