Yes, it's explicitly said in the docs that it's based/inspired by Seaside[1]. But note that - last time I checked - Nagare requires Stackless Python and not the standard interpreter. That's because Stackless lets you serialize tasklets and stack frames, which is impossible in normal Python without a custom C extension. It also lacked many useful features, like any kind of authentication handling (but, being WSGI compliant, you probably can plug some middleware to handle this).
