Cornelius posted a neat summary of the source code heft in KDE's main modules. It was also picked up by some of the general F/OSS community news sites.
Michael Meeks posted an blog entry showing other projects' line count next to KDE's while asking "the real question is not 'is KDE valuable' - of course it is; but how does it compare[?]" In a nicely concise table he shows that Ohloh pegs KDE at 5.5 million lines of code with GNOME at 15.7, Linux at 7.9 and OpenOffice at 8.5 respectively. That makes KDE's code base look smaller in comparison to these other projects, doesn't it?
Unfortunately, statistics are often hard to interpret when aggregated like that. Also unfortunately, Michael's blog doesn't accept comments to it (2000 called and it wants it's blogging software back? ;) so I figured I'd expand a bit on this here.
Cornelius's numbers, as well as the ones on Ohloh, only cover the modules we release as part of the periodic KDE Software Distribution. These are the modules that get known as "KDE x.y". What those numbers don't include is the rest of the code we work on under the KDE community umbrella. That would include all the apps in our Extra Gear repository such as Amarok (175,760 lines), Digikam (478,185 lines), K3B (101,320 lines) and Kaffeine (269,149 lines) to name the four largest. My checkout of Extra Gear contains 1,175,644 lines of code according to sloccount. Also missing from the numbers is the code in kdesupport for things like QCA, Nepomuk and Strigi, Akonadi, Phonon, taglib, KDE/Win utilities, etc. which combined represent some 433,208 lines of code according to sloccount.
Most significantly, however, is the omission of Qt itself. Ohloh weighs it in at 16,028,530 lines of code.
If we look at the Ohloh numbers for GNOME, Linux or OOo they are much more representative of the entire set of code associated with those projects. GNOME, for instance, includes Gtk+ and a comprehensive listing of applications worked on under the GNOME umbrella. That helps explain the 15.7 million number a bit more clearly.
With a similar amalgamation, KDE weighs in somewhere in excess of 23 million lines of code. Even then, nothing is said about code complexity, efficiency granted to applications by sophistication in the lower levels of the stack, etc. That just can't be reflected in such simple numbers as these. Still, it is an interesting data point to look at for what it is worth. (A sentiment that Cornelius shared in his blog entry as well.)
So does this tell us anything useful at all? Well, if nothing else it does show that there is a lot of F/OSS technology out there these days. Between the four projects mentioned here alone there are over 50 million lines of code, and those four projects, while large in their own rights, are hardly the bulk of F/OSS code. That's pretty amazing.