Besides the industries pjmlp mentioned (finance and insurance/banking), F# is also being used for data science/analytics/machine learning, distributed applicati

Besides the industries pjmlp mentioned (finance and insurance/banking), F# is also being used for data science/analytics/machine learning, distributed applications (on Azure and AWS) and bioinformatics. I also know there are at least a few companies building mobile apps and games with F# (e.g., in combination with the Xamarin toolchain).