James Gosling: the Canadian engineer who created Java

From Calgary to Carnegie Mellon

James Gosling was born in 1956 near Calgary, Alberta, in Canada. He earned a bachelor's degree in computer science from the University of Calgary in 1977 and then moved to Carnegie Mellon University in the United States, where he completed a PhD in 1983. His thesis was on the algebraic manipulation of constraints.

At Carnegie Mellon he built a lot of practical software. He wrote a version of the Emacs text editor for Unix and a version of Unix for multiprocessor computers. The Computer History Museum highlights one project in particular: he made a Pascal system written for one kind of workstation run on a different computer, a DEC VAX, by writing an emulator for the original machine. Years later he pointed to this work as the inspiration for the Java virtual machine.

Sun Microsystems and the Green Project

Gosling joined Sun Microsystems in 1984, recruited by co-founder Andy Bechtolsheim, and stayed for 26 years. One of his early projects, with colleague David Rosenthal, was a windowing system called NeWS, designed to work across different hardware and operating systems.

In June 1991 Gosling, Mike Sheridan and Patrick Naughton started a new language project known as the Green Project. It aimed to go beyond C++, and the excitement of the time about connecting televisions, phones, set-top boxes and home appliances pushed it towards controlling smart devices. The language was first called Oak, reportedly after a tree outside Gosling's office.

On 2 September 1992 the team first demonstrated Oak on Star7, a handheld controller with a graphical screen. Later attempts to sell the technology for interactive television did not succeed, and the group was folded back into Sun.

Oak becomes Java

The name Oak was already a trademark of another company, so around January 1995 the team held a long brainstorming meeting to choose a new one. Gosling later described the session as wild craziness, with people shouting out words. A short list went to the lawyers, Java was among the names that cleared, and product manager Kim Polese made the final choice.

Java was formally revealed at the SunWorld conference in San Francisco on 23 May 1995, and Netscape announced it would license Java for its browser. Time magazine named Java one of the ten best products of 1995.

Gosling did the original design of the language and wrote its first compiler and virtual machine. The central promise was that code written once could run on many platforms, because programmers always wrote for the same virtual machine. Today Java is used in desktop software, web servers, enterprise systems, embedded devices and mobile phones, and it is widely taught in computer science courses.

After Sun

Oracle acquired Sun in 2010 and Gosling left soon after. He worked briefly at Google, then wrote software for autonomous ocean robots at Liquid Robotics, and in May 2017 joined Amazon Web Services as a Distinguished Engineer, leaving in July 2024. He was named an Officer of the Order of Canada and, in 2019, a Fellow of the Computer History Museum.

The skills and habits that made the difference

The first was building many real tools. Before Java he had written editors, compilers, mail systems, window managers and satellite data systems. Each one taught him something about how software and machines fit together.

The second was reusing old ideas. The emulator he wrote as a student became the seed of the Java virtual machine more than a decade later.

The third was working in a team and adapting. Java began as a language for home devices, survived failed business deals and a forced name change, and found its moment with the web.