Montepetrum is free for personal/non-commercial use, AND commercial use.
Montepetrum is licensed under a Creative Commons Attribution-No Derivative Works 3.0 License: http://creativecommons.org/licenses/by-nd/3.0/
This means, that you can share the font as you like, but not make a new version of the font (e.g. an italic version) and publish it without my permission. Other than that, you are free to use it as you like in any way (mix it with other fonts/ change letters etc. etc.)
If you still have questions or comments, you can write to my email: email@example.com