Network data plane programming is a consequence of the evolution of the concept of control and data plane separation, stated two decades ago, and established on the Software-Defined Networking (SDN) architecture. The concept has been evolving since its initial implementation using the OpenFlow protocol, whereby an omniscient external entity, the controller, dynamically configures the forwarding of network devices, which are basically “dummies”. In this paper, we review network data plane programming languages, describing their theoretical characteristics and presenting examples and possible targets in order to compare them, in search of the best solutions to have a network of dynamically programmable devices that allow the network operator to deploy innovative use cases without depending on the manufacturer, promoting innovation. The main contribution is to gather in one place the existing languages, present them, and compare different features to help the operator and programmers. Overall, we conclude that today, the language with the most development and device targets is P4, although there are many developments based on XDP and eBPF that can be useful when implementing a programmable network solution.