1 -- How active is the team who is writing the JHC compiler?
The "Team" is John and Its not his day job afaik. Lemmih used to work on it before he forked it into "LHC" which has since evolved into a new (GRIN based) backend for GHC [1].
2 -- Is it complete Haskell? The author claims that it is; it compiled all programs that I wrote, but that does not mean much, because my programs are quite simple.
"Complete Haskell" has different meaning to different people. Perhaps it is H98 with FFI and concurrency? Hopefully it supports some more of the extentions.
3 -- Why the Haskell community almost never talks about JHC?
A) I suppose the lack of information wrt what extentions are supported is one reason I avoid it. My previous experience with JHC was also negative what with it not including/compiling necessary packages such as bytestring. B) I just installed it and ran it against a recent project: "evcaCLI.hs:1 - Warning: The pragma 'LANGUAGE' is unknown". It then failed to parse something futher on (unknown, poor error message... perhaps a bang pattern). C) Poor cabal integration, it would seem. I know I saw a recent jhc-7.2 patch for cabal but for now I use cabal 1.6.0.3 and the --jhc option doesn't seem to work. So these are mostly community issues with perhaps too much focus on a single compiler ecosystem, but they are real issues none-the-less. None of this is ment as a knock on JHC, which is cool but not yet of use to me personally. Thomas [1] http://lhc.seize.it/