That's a kind of historical confusion. Javassist is currently distributed under triple licenses MPL, Apache v2,
and/or LGPL.
Javassist was originally being distributed under MPL and then, when it was merged into JBoss, LGPL was
added. The interpretation between Marc (the founder of JBoss) and me was that, if someone redistributes
Javassist as a part of JBoss AS from JBoss, it is subject to LGPL. If Javassist is separately (or as a part
of third-party products) distributed, the distributor can choose either MPL, LGPL, or (now you can also choose)
Apache v2. (S)he can also choose any combination of the three such as MPL+Apache and MPL+LGPL.
According to the definition, JBoss (now redhat) choosed LGPL-only for distributing Javassist as a part of
JBoss AS etc.
Javassist is now also availalbe from Maven central. It would be much more preferable to your lawyers.
Another comment to your lawyers is that, when we added Apache v2 to the available license, all the
contributors agreed to that. (Unfortunately, the number of the contributors is small enough to easily make
the agreement.) So all of them agreed (by email basis) to the triple licensing.
Mike, is this clear?