A rough order of magnitude estimate would be hundreds of millions of dollars.<p>Java is nearly 30 years old and is widely used in enterprise backend systems, multi-platform desktop applications (e.g. IDEs, tools, games, etc.), and Android application development.<p>It did not get to where it is today without significant investments by large enterprise companies (Sun Microsystems, Oracle, Google, Amazon, Red Hat, IBM, etc.).<p>Many of those large enterprise companies are still deeply invested in Java and continue to support it in code / tooling contribtions and financial support. Java is the new COBOL and will likely continue to be used for the foreseeable future.