1. A method for performing version control for APIs of an operating system, said operating system capable of being revised by version and by platform, said method comprising: for a given API, creating metadata associated with a set of constructs of said API, said metadata comprising version indication; associating a version indication for each said construct of said API, said version indication indicating when said construct is revised into a given version of an operating system; defining a set of versioning rules for said constructs; when a new version of said operating system is constructed, enforcing said versioning rules to said constructs, according to said metadata associated with said constructs.