After downloading, double click the application to install.
For the Mac software:
1. In Safari go to the Safari menu and choose preferences.
2. Under the General tab uncheck the section that says "Open 'safe' files after downloading"
3. Then download the Mac software.
4. Double clicking it should unpack the zip file providing you with an application instead of the contents folder that you're probably getting now.
5. If not try Control+Clicking on the package and choosing BOMArchiveUtility in the open with option.
