R vs. F# vs. Dart

R provides a wide variety of statistical (linear and nonlinear modelling, classical statistical tests, time-series analysis, classification, clustering, ...) and graphical techniques, and is highly extensible.

F# is a mature, open source, cross-platform, functional-first programming language. It empowers users and organizations to tackle complex computing problems with simple, maintainable and robust code.

Dart is a cohesive, scalable platform for building apps that run on the web (where you can use Polymer) or on servers (such as with Google Cloud Platform). Use the Dart language, libraries, and tools to write anything from simple scripts to full-featured apps.