CIL (C Intermediate Language)

CIL - Infrastructure for C Program Analysis and Transformation

CIL (C Intermediate Language) is a high-level representation along with a set of tools that permit easy analysis and source-to-source transformation of C programs. [...] The main advantage of CIL is that it compiles all valid C programs into a few core constructs with a very clean semantics. Also CIL has a syntax-directed type system that makes it easy to analyze and manipulate C programs. Furthermore, the CIL front-end is able to process not only ANSI-C programs but also those using Microsoft C or GNU C extensions.

And the interesting part:

CIL has been tested very extensively. It is able to process the SPECINT95 benchmarks, the Linux kernel, GIMP and other open-source projects.

Maybe, in the future, we will need to write C by hand only very rarely, by using higher-level languages that compile to C. Not only that, but we may be able to maintain the legacy C code using higher-level languages. How about that ? :)