Eclipse distributions exist for most Intel / AMD-based platforms and for major UNIX. You should also be able to compile and create it yourself on other platforms.
The differences are mainly related to three problems:
1) Availability of the required Java distribution on the platform (for example, the late introduction of new versions of Java on the Mac).
2) 32bit vs 64bit
3) UI
Eclipse Swing, .
IDE, SWT . . Eclipse, . Mac OS, Carbon, Cocoa.