Hi there, I recently uploaded teh 1.3.14 source code, to start to look around the code. Actually, I humbly intend to actvely join GIMP's development along the next couple of months, if I can get enough of what is going on. ./configure, make && make install went as smoothly as one could ever dream, in a shinny install of MDK 9.1 - Congratulations to whoever manage this part. And them, I just started to hack around the code to take a grasp of how things itnerconnect around there. My intent almost worked out at first try (well, sometimes we might be able to say that a seg fault is ok as 'almost worked out', might not? ). But what I do need now is a faster way to go from edit code to running gimp. Make Install asctually eats out a lot of time on my system. Is it possible to run the gimp-1.3 binary generated from make straight, without make-installing it? How can it be done? And about my hack: I am trying with a "xor" layer combine and brush modes. I jsut based my work on the "multiply" mode, and worked on a copy of "pixel_multiply" in app/paint-funcs/paint-funcs-generic.h , and the related enuns in various other files. It seens like I am missing something yet - I will work on it tonight. The final effect is just too like the "difference" layer combine mode to be of any interest, I think, But if it get's interesting enough, I will mention it again. Thanks for all help. JS -><-