Yes. I created an internal language called "Lispon".

A lisp using json instead of sexprs. e.g. ["op", "arg", "arg"]. The team had a couple of requirements for a service we wrote: 1. Need to do batching. 2. Need to do stored-templated json responses based on data in our DB. 3. Need to not cost the project more than a week.

We had worked around #1 and #2 in awkward and debt riddled ways. (The client of the service was PHP with lack luster JSON processing, the service was java) So I whipped up Lispon and evaluator in about 3 days and had it integrated in another day.

It's lifespan was intended to be somewhat short, but like all code it's somewhat slow to get replaced and is doing its job adequately. JSON based sexprs are terrible to read.