I developed a tool for all Apex programmers who want to improve Apex development productivity.

https://github.com/DeveloperForceJapan/ApexTestPlus

This is a custom Ant task that makes testing Apex programs easier and faster and helps you implement TDD(Test Driven Development) when you use Force.com IDE/Eclipse.

After I had personally used this for more than a year, I felt sure that this would be useful for other people too and decided to publish.

Please refer README for more details and feel free to ask me if there is something you don't know.
Any feedback would be greatly appreciated.

Thank you!

There must be some way to tell because both the Profile detail page and the enhanced list view indicate whether the profile is custom.