Hello, A few months ago there was some discussion about an arbitrary magnitude integer library. I have now implemented such a library, which is located at http://groups.yahoo.com/group/boost/files/big_integer/. There are a few (incomplete) other libraries that provide the same kind of functionality. The main difference between this library and other libraries is that this library uses expression templates to avoid the creation of temporary values, which when the values become large provide an increase in performance. The library is not finished yet: most noticeably the test files are far from complete, but there are also a few others things like the documentation looks a bit ugly. Also a to-do is replacing the core operations like addition and multiplication by more efficient ones, and provide options to use external libraries like GNU MP. I am presenting you already with this library though, to see if it meets the desires for this kind of library, to see if there are things missing in this library, and maybe get some help from other members interested in further developing this library. best regards, Richard Peters