Gosling was with Sun Microsystems between 1984 and 2010 (26 years). At Sun he invented an early Unix windowing system called NeWS, which became a lesser-used alternative to the still used X Window, because Sun did not give it an open source license.
He is known as the father of the Java programming language. He got the idea for the Java VM while writing a program to port software from a PERQ by translating Perq Q-Code to VAX assembler and emulating the hardware. He is generally credited with having invented the Java programming language in 1994.
He created the original design of Java and implemented the language's original compiler and virtual machine. Gosling traces the origins of the approach to his early graduate student days, when he created a p-code virtual machine for the lab's DEC VAX computer, so that his professor could run programs written in UCSD Pascal. In the work leading to Java at Sun, he saw that architecture-neutral execution for widely distributed programs could be achieved by implementing a similar philosophy: always program for the same virtual machine. Another contribution of Gosling's was co-writing the "bundle" program, known as "shar", a utility thoroughly detailed in Brian Kernighan and Rob Pike's book The Unix Programming Environment.
He left Sun Microsystems on April 2, 2010, after it was acquired by the Oracle Corporation, citing reductions in pay, status, and decision-making ability, along with change of role and ethical challenges. He has since taken a very critical stance towards Oracle in interviews, noting that "during the integration meetings between Sun and Oracle, where we were being grilled about the patent situation between Sun and Google, we could see the Oracle lawyer's eyes sparkle." He clarified his position during the Oracle v. Google trial over Android: "While I have differences with Oracle, in this case they are in the right. Google totally slimed Sun. We were all really disturbed, even Jonathan [Schwartz]: he just decided to put on a happy face and tried to turn lemons into lemonade, which annoyed a lot of folks at Sun." However, he approved of the court's ruling that APIs should not be copyrightable.
He is known for his love of proving "the unknown"[clarification needed] and has noted but later clarified to be untrue that his favorite irrational number is √2. He has a framed picture of the first 1,000 digits of √2 in his office.
^McMillan, W.W. (2011). "The soul of the virtual machine: Java's abIlIty to run on many dIfferent kInds of computers grew out of software devised decades before". IEEE Spectrum. 48 (7): 44–48. doi:10.1109/MSPEC.2011.5910448. S2CID40545952.