This covers a range of different mathematical functions, all coded directly in Octave. Although there is some overlap with the existing special function libraries, it has new coverage and more robust implementations for some functions. (For example, though GSL is quite robust, it has limited support for complex numbers. The specfun package is a fairly limited coverage and some functions are not as robust / accurate as they could be.
It is not yet bundled into a package and put on octave-forge, though that is planned. But I've been very busy with "real life" and thought it might be of interest to have it released as it is (just a collection of .m files at the moment). There are some known issues but I think it could be of use already.
I'd love any feedback / comments / criticisms / questions.