haddock-0.7 interface file format

Hi, I've tried to use a haddock interface files like: ghc-6.4/share/ghc-6.4/html/libraries/base/base.haddock from the offical linux distribution under solaris. (Building the documentation under solaris did not work) Is the binary format of these files portable? If it's not portable it should not be located under "share"! Cheers Christian P.S. we use shared aterms as portable representation of haskell values with "drifted" instance generation (but reading and writing could be faster using arrays in the IO-monad instead of (pure) maps)