[justinsb]

This seems a much clearer overview: http://www.kythe.io/docs/kythe-overview.html

[akavel]

The http://www.kythe.io/ landing page seems to have the one-sentence summary:

"Kythe

A pluggable, (mostly) language-agnostic ecosystem for building tools that work with code."

For me, this is the best of all the listed "overviews", albeit still not fully clear.