I don't think it's the community that makes up for the bias, more importantly it's not normalized with respect to the size of the project, sure CoffeeScript won

I don't think it's the community that makes up for the bias, more importantly it's not normalized with respect to the size of the project, sure CoffeeScript won't have much lines per commit since 90% of the time the commit will be something like "make this slide-in twice as fast", where meanwhile Eclipse/Firefox/LAPACK etc. get done in Java/C/C++/Fortran. Also for the less widely used languages the sample is certainly much smaller and most projects are toy exercises. Anyway, C# is next to Assembly, and shell scripts next to Smalltalk, so what are we talking about here...