The first C "interpreters" I know of came out for Lisp machines in the mid 1980s: Symbolics' C compiler (http://www.bitsavers.org/pdf/symbolics/software/genera_

The first C "interpreters" I know of came out for Lisp machines in the mid 1980s: Symbolics' C compiler (http://www.bitsavers.org/pdf/symbolics/software/genera_8/Use... http://www.bitsavers.org/pdf/symbolics/software/genera_8/Use...) and Scott Burson's (hn user ScottBurson) ZetaC for TI Explorers/LMIs and Symbolics 3600s (now available under the public domain: http://www.bitsavers.org/bits/TI/Explorer/zeta-c/ http://www.bitsavers.org/bits/TI/Explorer/zeta-c/). Neither of them are interpreters, just "interactive" compilers like Lisp ones are.