Hi Gery There probably isn't a library to help - I've looked at extracting TrueType font metrics myself but abandoned it - TrueType fonts have a very complicated file format, and the spec is inadequate to code an implementation. TeX font metrics are probably simpler but obviously tied to TeX. Reading from file and being in IO is probably not so bad for a TeX like program - as TeX is essentially a 'compiler' a function from Tex to Dvi, i.e. compileFile :: TeX -> Dvi. For any significant compiler you are likely to have the work inside a monad made of a stack of monad transformers, so you can cleanly and fairly trivially add IO as the bottom layer of the monad stack - CompilerM - e.g. compileFile :: TeX -> CompilerM Dvi. Best wishes Stephen