I haven't downloaded the compiler yet, but here are a few things I like after reading the documentation.
- The C bindings are nice and simple in Crystal, with full support for structures and data types,
- "Globally named" symbols are a really great idea, especially in native binary when compiled to Int32's,
- OOP support seems polished with full support for encapsulation,
- Basic control structures and scope are also polished and familiar, while leaving beind the nasty parts from Ruby (i.e. `for do` vs `for`, Matz's regret for `do ... while`, etc)
- --hierarchy. Why haven't I seen a compiler support this by now?
A final point: "Everything is an object" and C-like efficiency seems paradoxical, but I'll look more into this. Objects may be abstracted by the compiler, but once compiled behave like any ole' statically typed system.