Julia is a programming language that is simple to write and scriptable like Python and R, but fast like C or C++. At 10 years, it’s a young language, so the ecosystem isn’t as large and mature as you want it to be. Maarten Pronk was an early adopter of the language in his research at Deltares, a Dutch research institute. In this lecture(s) he will introduce Julia, his motivation to use it and his OSS journey. Half of the lecture will be non-spatial, while the latter half will focus on the JuliaGeo ecosystem and showcased some of the possibilities of the Julia language. The JuliaGeo GitHub organization is intended primarily for the collaborative development of packages that are generally applicable across the geospatial and geosciences domains. For dealing with geospatial data, packages from the JuliaGeometry and JuliaImages organizations may also be of interest, and we will aim for good integration with those. Since the JuliaGeo organization aims to provide mostly general tools, more domain specific packages may be better suited for development in domain specific organizations. JuliaClimate is a nice example of such an organization that will be especially interesting to climate, atmosphere and ocean scientists. EcoJulia also provides some tools for generating and downloading spatial data sets, with a focus on ecological applications.