> We did have to manage it, and we had to do a fair bit of work behind the scenes to make it invisible to the users, but we succeeded at evolution.
I suspect that Linus' view on never, ever, binning old binary interfaces will mean that there will be (un)dead interfaces supported forever. My thoughts on a management plan look like:
(*) build a test suite round existing, in-use interfaces to maintain their intended functionality
(*) build a versioning API where a version-aware program can call in to use versioned interfaces
(*) attach version info to the existing APIs and handle a 'this interface is not implemented in your version of Linux' error
(*) develop a plumbing metalanguage to support disabled/legacy interface functionality via newer intefaces
(*) have all the interfaces configurable in the makefile, defaulting to enabled
(*) stop talking and show you some code