"Oscillation" is definitely the wrong word---I haven't seen any real instance of reverting to previous behavior without a good reason and a general consensus to settle on the one behavior. Although this mut thing has me nervous.
On the other hand, at least as far as I can see, "convergence" is also not a particularly good description. Admittedly, the code I have played with was written to exercise Rust's unique features, but going from 0.5 to 0.9[1] I got hit with a fair number of major changes. Take the M:N -> 1:N threading thing (and no, I still have very serious doubts about the long-term stability of "let's do both!"); that's almost completely transparent most code, but it's still the only significant difference between Java and Erlang.
[1] Yeah, I really need to find some time to catch up again.
On the other hand, at least as far as I can see, "convergence" is also not a particularly good description. Admittedly, the code I have played with was written to exercise Rust's unique features, but going from 0.5 to 0.9[1] I got hit with a fair number of major changes. Take the M:N -> 1:N threading thing (and no, I still have very serious doubts about the long-term stability of "let's do both!"); that's almost completely transparent most code, but it's still the only significant difference between Java and Erlang.
[1] Yeah, I really need to find some time to catch up again.