Why Use Non-Java Languages?

Since the JVM runs Java byte-code and not actual Java-code, it is possible to compile different languages into byte-code to be run on the JVM. Also, some languages can be interpreted at runtime on top of the JVM.

There are many different reasons to use other languages on the JVM. We’re able to quickly change code in production or development and not have to recompile our codebase. This can make development faster and more flexible. Also, other languages have features that Java does not have that can increase developer productivity and make new things possible, such as closures, mixins, and meta-programming. Although these languages are completely different from Java, they still run on the JVM and can interoperate with Java-based libraries.

The trade-off when using these other languages tends to be performance. However, the value of developer time gained is generally much more than the cost of the performance lost. In addition, Java 7 has added some features to the JVM to enhance the performance of dynamic languages (invokedynamic).

Java vs. JVM

Here’s a table of some popular JVM languages compared with features of Java: