does everything open (Apple's command-line launching program) does, and:
- opens URLs, directly or in your preferred helper application
- lets you specify applications by their four-character creator (e.g. 'ToyS') or Java-style bundle ID (e.g. com.apple.scripteditor), both of which allow you to move or rename an application without changing references to it
- asks applications to print documents, something the OS X Finder doesn't let you do any more
- launches applications in the background
- launches Carbon applications in Classic
- reports errors intelligibly
- shows information about any item on disk, including its file type, creator, data and resource fork sizes, dates and bundle ID (where applicable).