DylanAn object-oriented DYnamic LANguage, that aims at being compiled as efficiently as statically-compiled programming languages, while providing an unequaled development environment. It's a lot like a Lisp with an infix syntax and freed from backwards compatibility luggage. The design group hoped that it might bring dynamic languages to C++ programmers but that was before the Java seized the market with its hype. (but don't worry: even some Real Language programmers find Dylan nice).
Dylan was developed jointly by Apple, Carnegie Mellon University, and Harlequin Inc., with each group developing optimizing Dylan compilers for Mac, Unix, and Windows operating systems, respectively. Sadly, Apple abandoned the project half-way, and the CMU group moved onto different research topics, while Harlequin finally published Harlequin Dylan (formerly known as DylanWorks). Now, the difference between Apple and CMU is that because Apple was closed-source, all its code is now defunct, and no one will ever see it again, whereas CMU made its code public domain, which has been taken over by a bunch of joyful hackers. The CMU and Harlequin Dylan compilers are both actively maintained/extended, and both are cross-platform.