A rewrite can also mean a gradual change. A great example of this is the rewrite of 0install in OCaml from Python [0]. With such an approach you change module b

A rewrite can also mean a gradual change. A great example of this is the rewrite of 0install in OCaml from Python [0]. With such an approach you change module by module with old code and new code working side by side. It is of course not so easy, but it makes it possible to do on-line. A bit like with bits of Rust code that go in Firefox with each version. I would like to know if anyone participated in a similar gradual rewrite and how it went. It may be very hard for some architectures and also sometimes wrong architecture (prototype became production, some features were dropped along the way, a new feature is dog slow) may require big rewrite, even breaking APIs, then it would be impossible. But if one keeps API one can at least do comparison tests as more features are implemented. [0] http://roscidus.com/blog/blog/2014/06/06/python-to-ocaml-retrospective/ http://roscidus.com/blog/blog/2014/06/06/python-to-ocaml-ret...