Which came first, Java or Microsoft?

Microsoft came first, by 20 years. Gates and Allen founded Micro-Soft in Albuquerque.

Side by side

Java

Java was announced in May 1995, having started in 1991 as a project called Oak aimed at interactive television — a market that did not exist yet. Its promise was "write once, run anywhere", achieved by compiling to bytecode for a virtual machine rather than to a specific processor. JavaScript arrived seven months later and was named after it purely as a marketing decision; the two languages are unrelated.

Microsoft

Microsoft was founded in April 1975 to sell a BASIC interpreter for the Altair 8800 — a product they had demonstrated before writing all of it. It predates Apple by almost exactly one year. The hyphen was dropped in 1976 and the company moved to Washington state in 1979.