Haskell gurus, We have made a proposal to extend the Erlang `binary' data type from being a sequence of bytes (a byte stream) to being a sequence of bits (a bitstream) with the ability to do pattern matching at the bit level. This proposal has now been fully implemented all these at the level of the BEAM virtual machine and in the HiPE compiler. Most probably, they will be part of the next major Erlang/OTP open source release. (We write "most probably" because we do not really control what Ericsson desides to release as part of its open source system.) We wanted to evaluate the performance of our implementation and the succintness of our syntax, particularly against other `similar' languages. For this reason, we wrote five reasonably representative benchmarks, showing the things that one could employ bit stream pattern matching and bit-level comprehensions for. The benchmarks (drop3, five11, huffman, uudecode, and uuendode) have all been written in Erlang, O'Caml and Haskell. For some of them, C and Java versions exist. They can be found in the following homepage: http://bitbenches.infogami.com/ As you will see there, the Haskell numbers are significantly slower than those of Erlang and O'Caml. We are wondering why this is so. For each language, we have spent a considerable effort in writing the benchmarks in -- at least what we feel -- is the most natural and efficient way one can write them. The only constraint we impose is that for functional languages, data structures without any explicit mutation have to be used in the part of the program for which measurements are taken. Our experience in writing efficient (and beautiful) Haskell programs is close to (if not below) zero. Also, perhaps our mind might be suffering from severe case of strictness and might be completely unable to `think lazily'. So, we request your help in noticing obvious NO-NOs and stupid mistakes that we might have made. We even welcome completely different Haskell programs provided they adhere to the constraint mentioned above -- no mutation. Best regards, Kostis Sagonas and Per Gustafsson