our company has a bum policy and it reads "all software must be 1 version behind", I hate this and I cant change it. so that would mean that our production machine will only go as far as .NET 4.0 for now, only when .NET 5 is release can we move to 4.5! stupid, I know.so currently I am planning on proposing for dev machines to upgrade to Visual studio 2012 and target .NET 4.0 which is ok for now;We have some projects in the immediate future which would need a lot of asynchronous programming and I want to be able to use all the 4.5 syntactic goodness the async/await and all the rest of the improvements.so what are the options! accept "thats just life" and only target 4.0 and moan! or is there a way to target 4.5 in dev and import some 4.5 dll's into prod, is this even possible? ultimately is it possible to develop to take advantage of the 4.5 features in any way and deploy to 4.0? any advice please...