Awesome
Efficient, versatile logging tools for Haskell.
fast-logger
low-level and extremely fast logging tools. All Haskell logging tools that log to a Handle or generate formatted dates should depend on these.
wai-logger
add logging to your webapp. fast Apache style logger
date-cache & wai-logger-prefork
Obsoleted.
Please see package documentation of individual packages for more details, e.g: http://hackage.haskell.org/package/fast-logger