You've *got* to start learning to search first before asking all these one-liner questions: this information is freely available on the web and trivially findable.
Maybe you could start by telling us what *you* think the answer to this question is.
I agree. Here's the link: http://ej-technologies/jprofiler - if it wasn't for jprofiler, we would need to
run our stuff on 16 servers instead of 3.
subject: How to decide whether to use interfaces or abstract classes ?