I don't think anybody used it as describe in the original Out of the tarpit [1] (I hope I got the right paper :) Closest I saw might be the now defunct Eve lan

I don't think anybody used it as describe in the original Out of the tarpit [1] (I hope I got the right paper :) Closest I saw might be the now defunct Eve lang [2], because it was a reactive system based on datalog (?) semantics, so it looks like it is one of the few attempts, that played with some sort of relational semantics. Second I might consider could be C# with LINQ? This is probably the most interesting embedding of relational programming into a modern mainstream language :) Third, these-days you mostly see Functional Relational Programming, that seems to be trying to solve a similar problem. It drops the Relational entirely, but there still is large focus on state-management. [1] http://curtclifton.net/papers/MoseleyMarks06a.pdf http://curtclifton.net/papers/MoseleyMarks06a.pdf [2] https://github.com/witheve/eve-native https://github.com/witheve/eve-native