- Major syntax overhaul: self parameters now required, removed implicit self and several keywords (move, fail, assert, log), new lifetime and trait implementation syntax, and revamped use/import rules;
- Semantic changes include default move semantics for owned pointers, all foreign functions marked unsafe, unaliasable &mut, and updated macro scoping;
- Standard library reorganized with new containers, big integer support, and removal/replacement of many modules, plus toolchain shift to rustpkg and added benchmarking support