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The garbage collector for Microsoft's Common Language Runtime (CLR -- the VM for .NET) was written in Lisp originally and then transpiled into C.

Also, Apple's Interface Builder began its life as a Lisp program: http://vimeo.com/62618532

+1 for mentioning my friend Denny. I wrote an application that Experteliigence sold for me - lots of fun. Expertelligence had a high talent density.

Postgres started as a Lisp program, and turned out to be too difficult to develop in a mix of C and Lisp.

The Objectstore database was developed by former Lispers, who wrote an earlier object-oriented database in Lisp.