Shader Conductor is one of several open-source projects for going from one shading language to another. With Microsoft's Shader Conductor the focus is on converting HLSL to GLSL or SPIR-V (OpenGL/Vulkan), ESSL (OpenGL ES), MSL (Apple Metal), and older HLSL shader models. Shader Conductor can handle all shader stages, including geometry and compute shaders. Learn more about this new Open Source project from Microsoft.
Currently in the planning stages of a new open source project, CLyther, is a Python tool similar to Cython. CLyther is a python language extension that makes writing OpenCL code as easy as Python itself. CLyther currently only supports a subset of the Python language definition but adds many new features to OpenCL. CLyther exposes both the OpenCL C library as well as the OpenCL language to python.
This star and planet charting iPhone 3Gs app uses your current global position, heading, and accelerometer data to draw a current picture of the stars and planets around you. A small portion of the code is GPL licensed, but the bulk is BSD-style license or less restrictive. The app and source code make a great learning tool.