I convinced ITK to compile on OSX without the examples. Trying to build the examples though, gives an error: Insight/Code/Common/itkSliceIterator.h:22: valarray: No such file or directory when compiling the MIregistration example. Sure enough, the compiler can't find valarray.h. What is it? -- ______________________________ Robb Brown Seaman Family MR Research Centre Calgary, Alberta, Canada