OpenCL (Open Computing Language) is an open, royalty-free standard for cross-platform, parallel programming of diverse accelerators found in supercomputers, cloud servers, personal computers, mobile devices and embedded platforms. PoCL is a portable open source (MIT-licensed) implementation of the OpenCL standard (1.2 with some 2.0 features supported). In addition to being an easily portable multi-device (truly heterogeneous) open-source OpenCL implementation, a major goal of this project is improving interoperability of diversity of OpenCL-capable devices by integrating them to a single centrally orchestrated platform.