[Darmani]

Halstead complexity? Cyclomatic complexity? Those are just a couple of famous, old-school ones.

Software metrics is a major research area, and dates back to the 60s. The paper "Software Metrics: A Roadmap" has a good summary of the state-of-the-art as of 2000.

[Silhouette]

Could you, off the top of your head, give a rough idea of what cyclomatic complexity or Halstead complexity corresponds to a "large" project? In fact, given even a very simple code snippet, could you state on a cursory examination what these complexity values would be? Could most people reading this discussion?

If not, your alternatives don't serve the required purpose. Everyone gets that a project with 10 million lines of code is big. Whether it's bigger in any useful sense than another project of 8 million lines isn't really the point, and any alternative that doesn't have an immediate intuition for people reading the discussion isn't helping much.

[stonemetal]

http://www.neverworkintheory.org/?p=58

After controlling for lines of code, most complexity metrics become worthless.