The vast majority of actively evolving business software is written in Java these days. Java has long enjoyed the title of One Language to Rule Them All. However, in a previous post, The Next Big Language, I mention that I'm skeptical that there will be one language that is perfect for solving all possible problems in the future.
I might be overestimating the speed at which our profession is maturing. One of the reasons Java became the enterprise standard was because the wrong people were making decisions based on inadequate information and swarms of terrible programmers. I like to believe that we're moving away from those days, but then again, we definitely still have far too many NNPPs that need to be encouraged to find other employment. However, I do think it's inevitable that we move to languages targeted at specific domains and problems eventually.
We've already taken the first step. Games are a form of business software. Games are consumer products. However, game development has never been dominated by Java. I won't pretend to know about the game industry, but from what I hear it's been largely dominated by C++. However, these days Lua has enjoyed great popularity in the videogames industry.
The game industry has been using the right tool for the job for some time; however, other business are also starting to catch on. Many companies are using Ruby and Rails to build websites. There's no question that having a good group of programmers building your website using Ruby and Rails can provide a significant competitive advantage. Erlang is another language that targets a specific class of applications, and it provides huge advantages over the alternatives for those applications.
I think targeted languages raise some new interesting questions.
For the professional software developer, targeted languages may make it harder to switch domains. These days it's easy to get a job doing Java development in insurance, banking, advertising, and many other domains. If in the future all the banks are using a functional language focused on low-latency, you may find it harder to make the switch to an advertising agency with a shop that's using an object oriented dynamic language. It may not be long before selecting a language implies selecting a domain as well.
There will be implications for firms also. The pools from which companies hire from will get much smaller. It's very hard to hire a good Java developer these days, imagine what the picture is going to look like when there are 5-7 targeted languages that are widely accepted and the developer pool is split 5-7 ways.
There will also be questions about how many languages your organization will support. If you're a bank and you write your trading applications using the best language for the job, would you allow the intranet dev team to use a completely different language?
Like it or not, we're headed towards more targeted languages. It's probably worth considering the implications sooner rather than later.