It's worth an honorable mention toward the 47,000 line file containing the entire garbage collector for the C# runtime. It was originally written in lisp, then

It's worth an honorable mention toward the 47,000 line file containing the entire garbage collector for the C# runtime. It was originally written in lisp, then automatically translated to C++ by a script before .net was released. It's been hand maintained since and the folks at Microsoft have rejected attempts to refactor the code.