Note: This blog post is from 2012. Some content may be outdated--though not necessarily. Same with links and subsequent comments from myself or others. Corrections are welcome, in the comments. And I may revise the content as necessary.One of the many hidden gems in CF10 is that there's a new way to programmatically obtain the current instance name. In CF 6-9, we had to call a method in a JRun class. In CF10, they've added a new method in the Admin API.
The quick answer is that there's a getInstanceName method in the runtime.cfc of the Admin API. And yes, any user can execute this code. They do not need to BE an admin. You can use this in production code. For more, see below.
If that's enough to get you going, have at it. For more info, read on.