Adding to an old thread: http://www.haskell.org/pipermail/haskell-prime/2008-April/002441.html I like to note that I'm against this proposal. The example given in http://hackage.haskell.org/trac/haskell-prime/wiki/QualifiedOperators namely [Red..] can be easily resolved by adding a space, thus [Red ..]. I use qualified operators occasionally, since I use NumericPrelude and thus have to import some things from Prelude in a qualified way. As there will appear more and more infix operators in libraries along with more name clashes (e.g. recently discussed List.++ and Monoid.++), qualified operator names will become not so uncommon. Of course, to keep the spirit of infix operators, you will better define custom operators locally, but this is only reasonable if you use an infix operator more than once. The current syntax is also in a way consistent, since e.g. (+) coincides with a two side operator section, which is no longer true with the new proposal. Also (...) and `...` are dual, which is a nice property.