Perhaps the siren song of "isomorphic JS", where you can run the same code on the server and on the client? I can see the use case for having complex model and

Perhaps the siren song of "isomorphic JS", where you can run the same code on the server and on the client? I can see the use case for having complex model and validation code running on the client for speedy feedback and on the server for security, and perhaps also the idea you could render something entirely on the server when needed (eg for indexing and non-JS clients) and on the client when it's capable. Personally, I wouldn't want to touch server-side JS with a 10 foot barge pole.