Yes, source repository is a given. I am curious - you are saying that sequential work is the one preferred, i.e. check out sources, develop on one platform, then check sources in, switch to another platform, check out, build etc. I am wondering - is there a setup on a single machine where I can develop on a one platform and then send a "signal" to other platforms to start building from the same code repository, storing intermediates and targets in OS-specific directories.