Online proofing approval software provider Technologies used are Java, C, MacOS API. A Java applet for finding MacAddress of the client machine and to be used as licensing and authorizing process. Proved to be more complicated than our initial estimates as it had to deal with various combinations of Win32, MacOS 9, OSX, IE, Safari, Netscape, different signing methods etc. Also there was no straight method of doing the above in Java so we have to use different approaches for different OS including using JNI on MacOS 9.