legal issues re compiling other java libs?

[Heitzso <heitzso at growthmodels dot com>]

Trying to get my java app that uses freetts and axis
to compile with gcj, I find myself having to pull in
other java libraries:

axis:
   IBM's graphics.jar
   jimi from sun

freetts:
   IBM's graphics.jar

then, to build graphics.jar I'll probably have to pull in
other IBM or sun jars.

I haven't thought the legal issues when taking more generic
off the shelf jars, i.e. various apache or gnu jars and compiling
them down into shared libraries for the app.  But having to
reach into IBM's JDK and touch their jar's makes me wonder.

And I'm now wondering about even compiling gnu jars,
e.g. gnumail, and apache jars, e.g. blat-commons-blat.jar,
into a common app.

Without dragging in an IP lawyer, what is the common
thought on this?

Thanks,
Heitzso