For the DRM signing stuff, yeah I would guess you almost certainly do need Apple's toolchain. I wouldn't be surprised if you can use other tools to do everythi

For the DRM signing stuff, yeah I would guess you almost certainly do need Apple's toolchain. I wouldn't be surprised if you can use other tools to do everything else though - indeed, Adobe was just using LLVM to output ARM assembly for their Flash-to-iPhone compiler. From the legal side, I haven't seen any requirement that you use their toolchain - again, it's just been the "originally written in" stuff.