This question might be slightly subjective, but I am unsure where else it would be better suited.
I have used Orchard on a number of projects where the server was Windows Server based - integrating with AD, SQL etc to provide a MVC based portal - like stealing candy from a toddler!
I have been exploring MonoTouch recently, and installed Orchard on OSX under ModMono as per http://docs.orchardproject.net/Documentation/Running-Orchard-on-Mono.
It all seems to run fine, and fast, but I am unsure whether to back this on a commercial venture. I have always used MySQL or MSSQL as the DB, whereas my current install is running PostgreSQL - something new (which is always good).
Does anyone know of any sites which use Orchard running on Mono, with ModMono (Apache2) and PostgreSQL?
I plan to deploy to a cloud server running CentOS and Mono to do further testing before going any further, but think it could be an exciting avenue to explore.