Java the language is almost irrelevant. It's the design of the Java Virtual Machine. And I've seen compilers for ML, compilers for Scheme, compilers for Ada, and they all work. Not many people use them, but it doesn't matter: they all work.

James Gosling’s quote, "Java the language is almost irrelevant. It's the design of the Java Virtual Machine," reflects his belief that the success of Java as a programming language is not solely due to its syntax or structure, but rather because of the underlying design of the Java Virtual Machine (JVM). Gosling emphasizes that the JVM—the platform that allows Java programs to run on different systems without modification—is what truly made Java powerful and widely adopted. The JVM abstracts the complexities of hardware, making it possible to execute Java programs across various platforms with ease.

Gosling further elaborates, "And I've seen compilers for ML, compilers for Scheme, compilers for Ada, and they all work," suggesting that there have been many programming languages and compilers (tools that translate source code into executable programs) developed over time, including ML, Scheme, and Ada. Despite the variety of languages, he points out that they all "work" in the sense that they can perform their intended functions, but they did not achieve the same level of widespread use as Java. This illustrates that while a language and its compiler are important, they are not the sole factors in determining success; the overall design of the system in which they operate is crucial.

The mention of "not many people use them, but it doesn't matter: they all work" reinforces the idea that even though other languages and their compilers are functional, they did not have the same impact or widespread adoption as Java. Gosling is making the point that Java's success is largely due to the JVM's ability to make cross-platform development possible, which allowed developers to create software that could run anywhere, regardless of the operating system.

Originating from Gosling’s role as the creator of Java, this quote highlights the technical insight that led to the language’s massive success in the software development world. Gosling’s emphasis on the design of the JVM underscores how critical underlying system architecture is to the usability and adoption of a programming language. The JVM allowed Java to transcend its syntax and become a versatile, cross-platform tool, which ultimately made it one of the most widely used programming languages.