For the time being, Rembrandt's main developer (FredB) is not actively involved in FlightGear, and Rembrandt must be considered "unmaintained" currently. However, there are 2-3 overlapping efforts, some of which were discussed on the developers mailing list. First of all, there's Zan's newcamera branch, which has never been merged with FlightGear, but which exposes FlightGear's rendering pipelines to XML/fgdata space via the effects framework - which basically means that large portions of Rembrandt could be moved out of the C++ code back into GLSL/effects space, which is something that was originally discussed by a few core developers. This has never materalized, because Zan's work took place pretty much at the same time when Rembrandt was being developed. Likewise, some technical challenges could be easily addressed by exposing each rendering stage to a [[Canvas]] texture, which would mainly require two new features: 1) [[Canvas_Development#Supporting_Cameras|supporting camera views as a new Canvas::Element]], and 2) [[Canvas_Development#Effects_.2F_Shaders|supporting effects/shaders]] per Canvas/Element.
From then on, most [[Howto:Use_a_Camera_View_in_an_Instrument|Rembrandt-like functionality, including mirror views, tail cameras or FLIR-like processing]], could be fully implemented and maintained by fgdata contributors familiar with the effects framework and shaders, without necessarily being specific to just deferred rendering: