Here is some data on downloads of Haskell libraries and apps on Hackage, for the first quarter of 2010.
Hackage is the central repository of open source Haskell libraries and tools. Once they install the Haskell Platform, users get more libraries from Hackage, via “cabal install”.
Headlines
March was the most popular month for Hackage ever. And we’re closing in on 2000 packages, and 2 million “cabal installs” in the next month or so.
Totals
Total cabal packages: 1976. (+ 256 in Q1).
Total contributing developers: 533
90 day moving average: 11.5 packages per day uploaded (up from 10.5).
Total downloads from Hackage 2007-present: 1.88 million (up 350k in Q1)
Downloads in March 2010: 145,752 (new monthly record)
Top of the Pops
The top 15 most popular libraries in the first quarter were:
- HTTP
- zlib
- parsec
- utf8-string
- binary
- QuickCheck
- network
- Cabal
- haskell-src-exts
- mtl
- regex-base
- uniplate
- regex-posix
- X11
- ghc-paths
Top 15 most popular applications in Q1:
- cabal-install
- xmonad
- cpphs
- haddock
- happy
- hscolour
- darcs
- alex
- pandoc
- hlint
- leksah
- yi
- agda
- texmath
- gitit
Honorable Mentions
- The deepseq is in the top 20 packages of the year.
- HaXml and HDBC remain the most popular xml and database libraries (though xml-light is closing in)
- wxHaskell is rising up, as the only cabal-installable major gui library
- vector and text are quickly rising as the preferred arrays and unicode libraries
You can read all the Q1 data for your favorite packages, and ranked by Q1 popularity.
And for non-Haskellers, how does your favourite open source community compare?
Control.Monad.Writer 
What’s to say that people aren’t installing pandoc as a _library_ and not an executable? :p
It’s great to have some data like this to see into the vibrant Haskell community. Thanks Don!
Also, I’m curious how you picked the honorable mentions. Are these projects related to your own work, or are they generally considered “interesting” by the community perhaps?
Oh, the xml and db ones are an often-asked question (e.g. “Which Haskell DB lib should I use?), while text and vector are on the path to becoming standard libraries in their domain (unicode and arrays, resp), so I chose those because they are rising fast.