I am currently re-implementing in Lisp the C++ ERP application used in the company I work for.
Lisp is our "Secret Weapon" since it allows us to reduce developement time by a factor of five when compared to C++ and implement new features on the fly without having to wait for boring nightly build or to waste time in debugging hidden memory leaks due to dangling pointers.
Since we opted for a browser based interface the GUI API was not an issue anymore and we were free to use the best server side language available.
After some attempts with PHP/Pyton/Java Common Lisp was our choice for these reasons:
1) Good relational database support ( see CLSQL )
2) Speed ( easily outperfomed PHP/Python/Java)
3) No more edit-compile-link-debug cycle
4) CLOS ( try to use C++ template and then move to CLOS generic methods. Do you feel better ?)
5) Excellent for modelling bussiness rules and business objects (the job-shop scheduler was a nightmare of spagetti code when modeled with C++ classes).