Instrument Apps and Servers

Andrew Wilcox published an interesting article on DeveloperWorks which details the use of the Java 5.0 agent interface combined with aspects to produce an interactive, pure java, profiling tool. The article introduces asm, an interesting byte code manipulation framework, and an eclipse plug-in supporting asm.
Implicitly the article exposes some aspects of the term 'open':

• Wilcox presents code anyone can use
• Asm is open source
• While we can complain that Java is not truly 'open', it is open enough that bytecodes can be manipulated in truly useful ways by independent developers.
• Eclipse is 'open' not just in the sense its source code is open, but in the sense the resulting ecosystem is open to all manor of contributions

Profiling presents a developer's perspective of instrumentation. Runtime monitoring is another. The approach Wilcox outlines suggests an useful path for making applications (clients and servers) somewhat aware of their footprint.