One of the greatest finds of the past 12 months has to be New Relic. Its monitoring and performance tracking in a box is just amazing, and shows what modern SaaS solutions should be.
New Relic is a great application tier monitoring solution, and while I would love it to do many more things, its still amazing how much it can do.
It is still lacking a bit in non application monitoring, so can’t hold all the cards at the moment, but works well alongside other platforms.
Don’t write this off as a Java tool, I know I initially did, but we have had it run against PHP stacks with just as much useful information generated.