In such research, Spinelle computed the amount of source code that are not of compiler's interest from 30 OS projects. The results showed that for most of projects, more than 60% of source code is composed by code used to facilitate the source code understanding. The Figure bellow summarizes the results (click to expand).
I absolutely agree with him when he says that source code is the most important asset. And current, in OS world, Reuse is all about reusing source code. Thus, to understand what some source code does and how it does is very important to reuse it.
Efforts have been concentrated to defined architecture and design definition process (among other software aspects) to facilitate software reuse, however we are still looking at the source code before to reuse it. Thus, such efforts seem to forget that some programming language (actually source code) will be used to make the project runs.
Furthermore, most of projects analyzed by Spinelle is composed by successful open source projects; another reason to believe that source code is the most important artifact of software development ever.
So remember, if your project is going to be evolved on the future, the source code is probably the first place where developers will look at.
