Chapel Principles and Features
According to the information provide don the Chapel website, the programming language is designed from principles first, rather than by extending an existing language. Chapel builds on concepts and syntax from many languages, however its parallel features are most directly influenced by ZPL, High-Performance Fortran (HPF), and the Cray MTA/Cray XMT extensions to C and Fortran.
It supports a number of features including multithreaded execution model via high-level abstractions for data parallelism, task parallelism, concurrency and nested parallelism.
Chapel is being developed in an open-source manner at SourceForge and is released under the BSD license. Development of Chapel is led by Cray Inc., in collaboration with academia and computing centers.