Hello
We are using Sonar and so far is the best software after trying few out there.
Sonar support is great and also very affordable.
You can find more info at http://www.sonar.software
The other one is Powercode, its ok, but you need to but the BMU unit they have in order to do rate limiting at the edge, so it has his limitations.
Powercode support is great too.
There is also Wispmon, but I will stay away from this one, its windows based, and support is the worse I ever seen.
Cheers