People get excited about CL, so they use Google to search for some tutorials. Then they notice all the parentheses and quickly abandon it.

On a more serious note, i'm quite interested in hearing a realistic explanation.

Ah, it's Google Trends again, the world's most famous chart with no units.

They should put a link to How to Lie With Statistics on every page.

Well at least we can compare ist to other things, like c++: http://www.google.com/trends?q=lisp%2C+c%2B%2B&ctab=0... Sadly lisp is in a steady decline now, just like C++. Are the old languages dying?

The obligatory quote is "Lisp doesn't look any deader than usual to me" (David Thornley).

By way of comparison, it's got similar search volume as Algol: http://www.google.com/trends?q=common+lisp%2C+algol&ctab... . It loses to Erlang and OCaml: http://www.google.com/trends?q=common+lisp%2C+erlang%2C+ocam... , and Clojure: http://www.google.com/trends?q=common+lisp%2C+clojure&ct... . It's well below Haskell: http://www.google.com/trends?q=common+lisp%2C+haskell&ct... .

Interesting peaks.

Unfortunately I would guess the peaks are simply due to the incredibly low search volume (I say this as the owner of the site that's the second search result for "common lisp documentation").

I would guess that the search volume has been hovering around the cutoff for what gets recorded in the google trends database. Like a noise gate : http://en.wikipedia.org/wiki/Noise_gate