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!