We highlight the sustainable aspects of the newly developed Julia language: which is an excellent tool that can be used as a tool developing for mathematical modelling applications. Julia builds on modern notational- and language design principles that can lead to more compact and readable source code, close to mathematical notations. Numerical modellers can – in principle – use Julia and its programming/coding environment for implementing, understanding, and testing new algorithms. The benefit of the language is that – if necessary – the algorithms can be scaled up and run on a massive scale without code-level changes. In the article we present the distinctive features of Julia; the presentation is based on the Python language and on novel programming concepts, followed by a few examples that highlight Julia features that can make this language a popular teaching and research tool.