Key features include:
HIP is very thin and has little or no performance impact over coding directly in CUDA or hcc "HC" mode.
HIP allows coding in a single-source C++ programming language including features such as templates, C++11 lambdas, classes, namespaces, and more.
HIP allows developers to use the "best" development environment and tools on each target platform.
The "hipify" tool automatically converts source from CUDA to HIP.
Developers can specialize for the platform (CUDA or hcc) to tune for performance or handle tricky cases
https://github.com/ROCm-Developer-Tools/HIP
Interesting Use Case
We ported CAFFE to HIP http://gpuopen.com/ported-caffe-hip-heres-happened/