These are all tools that are compatible with Macs(OSX 10 and up). I am not sure if they would work for the classic OSs, but if they do, let me know. I tried to be as accurate as possible with the creator names. If I gave credit to a wrong person or spelled a name wrong, please let me know. Also, if there are any other Mac Tools I should add, please LET ME KNOW through a post. Please rep if this is helpful.

Rominator(ROM Editing tool) By HankChill
Direct Download

CocoDS(Early, but nice ROM Editing Tool) By CocoDS Team
Direct Download

DLDI Drop(Drag and Drop DLDI Patcher) By Jan Kempling
Direct Download

DS TrimDrop(Drag and Drop ROM Trimmer) By Jan Kempling
Direct Download

Hope this helps all of you Mac-users .