Originally Posted by SpaceToad
Reaper does have a feature called "Rearoute", which allows 2 way audio communication between Reaper and another program running their Rearoute ASIO driver (such as Reason), although so far without midi synchronization, midi out may change this however. Also, the latency is not perfect, partly because the signal has to travel to and from reaper to reason 2 or three times, once from reason to reaper and back again to use reaper as makeshift fx sends or inserts, and then again to reaper so you can hear the master out.
I wasn't aware that Reaper had that. I also use Reaper inside Pro Tools to run some of my VSTi's that don't play nice with Pro Tools even when wrapped with FXpansion's VST to RTAS wrapper. I didn't know about Rearoute. I need to check that out. I've wanted to be able to send audio from a PT audio track to Reason in order to use certain fx plug-ins that I have in VST format only (but won't wrap well). Wonder if this might work for that.