You cannot as of yet run direct x nativley on MACOS 9x and MACOS X.
You can run them via an emulator called VirtualPC and some public distributed applications that just emulate a PC shell.
You could install Windows with some tricks on your mac but it involves messing with a cut down version of Os9 and the finder and VirtualPC, the best performance is vaired from 40 - 75%.
There are two basic languages for Mac that are kind of similar to DB, METAL BASIC and TNTBASIC, metal is free and TNT costs about $50.
IF someone writes a DirectX wine lib for OSX then it may just the thing to emulate DirectX games for the newest MacOS, As you may know OSX is based on the unix BSD kernel.
C / C++ and JAVA at the moment are a lot easily ported as well as if your game was Written with OPEN GL in mind as compared to DirectX.
Game Sprockets make it even easier for OS9 based coding but the future for mac is a unix environment so its probably more advisable to look into unix OpenGL game coding if you want to go hardcore.
CodeWarrior is a great development package for macintosh coding.

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