You can't do much with Dart today. It's designed to run on either the client or the server (a la Node.js), but the only way to run client-side Dart code so far is to cross-compile it to JavaScript. Even then it doesn't work with every browser. But because Dart is released under a BSD-style open source license, any vendor that buys Google's vision is free to build the language into its products. Google only has an entire industry to convince.
Experimental programming language No. 2: Ceylon
Gavin King denies that Ceylon, the language he's developing at Red Hat, is meant to be a "Java killer." King is best known as the creator of the Hibernate object-relational mapping framework for Java. He likes Java, but he thinks it leaves lots of room for improvement.
Among King's gripes are Java's verbose syntax, its lack of first-class and higher-order functions, and its poor support for meta-programming. In particular, he's frustrated with the absence of a declarative syntax for structured data definition, which he says leaves Java "joined at the hip to XML." Ceylon aims to solve all these problems.
King and his team don't plan to reinvent the wheel completely. There will be no Ceylon virtual machine; the Ceylon compiler will output Java bytecode that runs on the JVM. But Ceylon will be more than just a compiler, too. A big goal of the project is to create a new Ceylon SDK to replace the Java SDK, which King says is bloated and clumsy, and it's never been "properly modernized."
That's a tall order, and Red Hat has released no Ceylon tools yet. King says to expect a compiler this year. Just don't expect software written in "100 percent pure Ceylon" any time soon.
Experimental programming language No. 3: Go
Interpreters, virtual machines, and managed code are all the rage these days. Do we really need another old-fashioned language that compiles to native binaries? A team of Google engineers -- led by Robert Griesemer and Bell Labs legends Ken Thompson and Rob Pike -- says yes.
Go is a general-purpose programming language suitable for everything from application development to systems programing. In that sense, it's more like C or C++ than Java or C#. But like the latter languages, Go includes modern features such as garbage collection, runtime reflection, and support for concurrency.
Equally important, Go is meant to be easy to program in. Its basic syntax is C-like, but it eliminates redundant syntax and boilerplate while streamlining operations such as object definition. The Go team's goal was to create a language that's as pleasant to code in as a dynamic scripting language yet offers the power of a compiled language.
Go is still a work in progress, and the language specification may change. That said, you can start working with it today. Google has made tools and compilers available along with copious documentation; for example, the Effective Go tutorial is a good place to learn how Go differs from earlier languages.
Experimental programming language No. 4: F#
Functional programming has long been popular with computer scientists and academia, but pure functional languages like Lisp and Haskell are often considered unworkable for real-world software development. One common complaint is that functional-style code can be difficult to integrate with code and libraries written in imperative languages like C++ and Java.
