I tend to peek at www.tiobe.com for an occasional laugh, as these people claim to measure "programming language popularity". According to TIOBE, they use meta data from search engines to calculate their "index".

The October headline reads: "Lightweight Java language Groovy enters top 20". Although I never took this data serious, this one did spark some additional serious doubt. Not long ago, Groovy did not even appear in the top 50. Did I miss something? It is known that TIOBE changes their metrics on a monthly basis, occasionally catapulting some languages up and down the scale. Last month the F# crowd was cheerful, as their language got a 250% (or so) boost.

Now for the fun of it, let us consult a range of search engines ourselves, to find the secret recipe behind the TIOBE index, and confirm the dominance within the largest stake holders in JVM languages next to Java:

---- Google.com ----

(general search engine; Date filter: Past year)

"Scala Programming"             7,320
"Programming in Scala"          4,570

"Groovy Programming"            2,750
"Programming in Groovy"           190

"Clojure Programming"           2,280
"Programming in Clojure"          451

---- Bing.com ----

(general search engine)

"Scala programming"       32,800
"Programming in Scala"    31,600

"Groovy Programming"      16,400
"Programming in Groovy"    2,920

"Clojure Programming"     11,400
"Programming in Clojure"   3,320

---- Amazon.com ----

(books etc.)

Scala Programming       62
Groovy Programming      37
Clojure Programming     32

---- Wikipedia.com ----

(encyclopedic articles)

"Scala" "Programming"   377
"Groovy" "Programming"  253
"Clojure" "Programming" 139

---- Indeed.com ----

(job offers)

scala & programming     802
groovy & programming    764
clojure & programming   382

---- scholar.google.com ----

(academic publications)

Scala programming       1,6300
Groovy programming       3,620
Clojure programming        836

---- Stackoverflow.com ----

(programming Q&A site)

[scala]        19,246
[groovy]        6,999
[clojure]       5,991

---- Github.com ----

(open source hosting; lines-changed according to 

Scala   136,412,480
Groovy   46,635,343
Clojure  44,527,630

---- Reddit.com ----

(social news)

clojure subscriptions   4,644
scala subscriptions     4,524
groovy subscriptions      715

----

Summary so far: Notice any trends? Given the above data, it seems that TIOBE is not taking these sources properly into account...

However!! We forgot to take one additional source into account:

---- Twitter.com ----

(social micro blogging; number of tweets by creator of language)

glaforge        20,055
odersky            469
richhickey         231

Conclusion: Clearly, Groovy is the most popular JVM language!