Beyond Java - Bruce Tate [89]
C#
C# (pronounced see sharp) is a programming language that fills the role of Java for the .NET platform. There's not much to say about C# in a book called Beyond Java, because it's built to be similar to Java. You'll see a few minor exceptions, like reliance on unchecked exceptions rather than checked exceptions, and some syntactic sugar. Many of the recent changes in Java, like annotations and autoboxing, were introduced to keep up with .NET. For the most part, though, those looking to trade in Java and simultaneously lose their problems will find a whole new stack of problems, with a similar size and shape. C# is merely Java's evil twin.
Still, Microsoft seems willing to separate old versions of C# to a new language, under development, called C Omega . This language would potentially make some significant strides forward, and possibly even break compatibility with C#. Such a language could potentially offer the features of much more dynamic languages, with the commercial backing of Microsoft, and the CLR as a portable virtual machine. It bears watching. Still, it's proprietary, and many won't give it a serious try for that reason alone.
Other languages on the CLR
What's intriguing about .NET is not the Microsoft languages. It's the promise of open source languages on the CLR. Right now, since most of Microsoft's energy is undoubtedly focused on Visual Basic, C++, and C#, you're not going to see a library that's built to take advantage of important concepts like code blocks and continuations. Still, Microsoft actively courts insiders in the Ruby and Python communities, so you could see credible implementations of those languages soon.
A weakness and a strength
.NET and the CLR have one major problem: Microsoft. Sometimes its weight and muscle work in your favor, and sometimes they don't. It's not likely that the CLR will ever run as well on other platforms as it does on, say, Linux. With Microsoft's heavily proprietary stance and a complete lack of portability, it's tough to see the Java community embracing .NET. You may be surprised that I don't think Microsoft's posture will remain so pervasively proprietary, especially on the server side.
I've said before that market leaders want to be proprietary. All others need open standards to compete. Microsoft is simultaneously the market leader for client-side operating systems, and lumped in with everyone else (or with Internet and Enterprise development). Proprietary frameworks make sense on the client, where Microsoft has had a near-monopoly for a long time now. They make a little less sense on the server side, where they've been unable to crack the market for medium and large systems. In time, I believe that Microsoft will recognize this reality and jump on the open source software bandwagon. I'm not the only one who thinks so. I sit on the expert panel of NoFluffJustStuff, one of the most successful and influential Java conferences outside of JavaOne. Stuart Halloway, one of the most respected Java consultants in areas such as metaprogramming and reflection, feels strongly that Microsoft will be the biggest open source vendor in the world, and Dave Thomas seems to agree.
If Microsoft does happen to move toward open source software in a credible way, and the Java community recognizes this, Microsoft will open the door to Java on the CLR, and more importantly, to the languages beyond.
Minor Contenders
Now, it's time to put on an asbestos suit and my +4 plate mail. I debated whether to include any sections on Perl, Lisp, PHP, or Smalltalk. They're fantastic languages in their own right. I just don't think they're next.
If you're deeply religious about any of these languages, you can just read these one-sentence summaries, and skip to the next section: Perl's too loose and too messy, PHP is too close to the HTML, Lisp is not accessible, and Smalltalk wasn't Java.
If you already feel slighted and you must read on—if you're a language cultist and I've mentioned your pet language in also-rans, or worse, didn't mention