If you tan to hide acne on black skin, nothing will be different (unless you are using skin lighteners or benzoyl peroxide, in which case exposure to the sun may cause the formation of black spots on your skin, in addition to any blemishes that may be on your skin).
Applets are designed to be embedded within an HTML page. When a user views an HTML page that contains an applet, the code for the applet is downloaded to the user's machine. A JVM is required to view an applet. The JVM can be either a plug-in of the Web browser or a separate runtime environment.
Apple itself jumped into Unix to create OSX and made a great version of it. I can only guess Microsoft isn't ignorant about the great improvements Windows could get if it was ever built over Unix and that they definitely have very different reasons to stay on their code (politics, strategies, marketing, history, etc.).