workflow definition language - is there a leader

Hi,

Is there a leading workflow description/definition language?

We have to build an employee onboarding webapp. It takes a new hire 
through the steps to read certain docs and fill out certain forms 
associated with their job type/level. The new employee, the new 
employee's manager(s) and HR staff should be able to sign off on tasks 
the hire completes.

Is there a good fit that exists? And/or is there a leading language that 
can handle this type of thing?

Also, do you know of any leading java libraries that support the language?

thanks,
-Rob