integrating output from external program to emacs, ala gcc, grep

[glen stark]

Hi everyone.

I'm writing a little tool that parses some code, and identifies likely 
candidates for refactoring.  Now what I'd like to do is be able to call 
that from emacs, and use the 'next error' function like I do when using 
gcc (via compile), or when I grep in the eshell.

So what do I have to do so that emacs can use my tools output?  I suppose 
there's some standard output format defined to allow tools to jump to 
errors.  Could someone point me to the documentation?

I guess the easiest thing to do is call the tool from the compile 
command.  What are the other possibilities?  How do I get it to run like 
grep does in eshell for example?

If anyone has tips that might save me a little time here, or result in a 
better implementation,  I'll be very grateful.

Thanks,

Glen