For Macs, DVDSP is pretty much it. For web links you can use Sonic’s eDVD which works great or there’s another application available but I cant remember the name – I hope someone else can lend a hand here.
A thing to remember though – The DVD spec was designed without the web in mind so there will be incompatibilities with this kind of authoring.
eDVD uses Interactual Player – which most newer PC have and will most likely self install but Mac users will have to manually install it