Oh no, more programming languages!
There certainly is a practical limit on how many languages a project can take.
Maintenance of all of them might prove to be difficult. However, sometimes
the usual languages are not enough. For example, GGZ uses the M4 macro language
for a lot of its configuration. The Make syntax, which can be considered a
partially declarative language, is similarly present in many packages.
Some Haskell code exists as a proof of concept Sudoku implementation.
It's the mix which makes it interesting!