[jacquesm]

It's a copyright violation if it isn't cleanroom, that means you don't get to re-license it under different terms. It will count as a derivative work under copyright law.

[mentat]

I'm sorry but this doesn't make any sense. If you merely read the code for another open source implementation before implemented something totally different that shares a separate publicly documented configuration language it's derivative. I'd be appalled at a judgment that upheld that view.

[paulgb]

For what it's worth, Monit says it's not clean-room but Mike says it is (https://twitter.com/mperham/status/519165523473358848).

[jacquesm]

That will be the sticking point. Up to Monit to prove that it it isn't, which should not be too hard if it isn't.