Recently multi-core processors have become very popular in computer systems. It allows multiple threads to be executed simultaneously. The advantage of multi-core comes by parallelizing codes to expand the work across hardware. Furthermore, this can be done by using a parallel environment developed by M.I.T. called Intel Cilk Plus, which is design to provide an easy and well-structured parallel programming approach.      Intel Cilk Plus is an extension of C and C++ programming languages that describes data parallelism. This extension is very helpful and easy to use among other languages in this field. It has different features including keywords, reducers and array notations etc. In general, this article describes Intel Cilk Plus and its features. In addition, Unified Modelling Language, activity diagrams are used in term of graphical modelling of Intel Cilk Plus by describing the process of a system, capturing the dynamic behaviour of it and representing the flow from one activity to another using control flow. Later on Intel Cilk Plus keywords and UML diagrams tools will be evaluated, a comparison of different UML modelling tools will also be provided.