Hi cameron

I'm in the US so I will reply a bit and after other people will certainly complement.

Hi All.

We need to set up a REST server for certain services and I am wondering what helper classes exist that work with Seaside 3.1.

with Seaside-Rest you get REST support.

Additionally, do they work on gemstone?

I do not know but I would not see why it would not.

Also, what support tools/frameworks would you recommend for JSON I/O?

NeoJSON from sven
There is a chapter in the PharoForTheEntreprise book

Thanks in advance,
Cam