At the technical level the Oracle ‘Java’ lawsuit against Google is not really about Java at all. The patents cited in the lawsuit (5,966,702, 6,061,520, 6,125,447, 6,192,476, RE38,104, 6,910,205 and 7,426,720) involve a variety of techniques that might be used in the implementation of a virtual machine supporting JIT compilation for software written in any language; Oracle does not get into the specifics of which parts of Android make use of these patented techniques (Google has not released the Dalvik source code). With regard to the claimed copyright infringement, I have no idea what Oracle claim has been copied; as I understand it Android uses Apache’s Harmony code for its Dalvik VM runtime library, but there is a possibility that it might have used some of Oracle’s gpl’ed code.
No doubt Google’s lawyers will be asking for specific details and once these are provided they have three options: 1) find prior art that invalidates the patent, 2) recode the implementation so it does not infringe the patent or 3) negotiate a license with Oracle.
My only experience in searching for prior art was as an adviser to the Monitoring Trustee appointed by the European Commission in the EU/Microsoft competition court case; Microsoft’s existing patents were handled by a patent lawyer and I looked at some of the non-patented innovations being claimed by Microsoft.
The obvious tool to use in a search for prior art is Google and this worked well for me provided the information was created after the mid to late 1990s. The cut-off date for historical searches seemed to be around 1993 (this all happened before Google Books was released). Other sources of information included old books (I had not moved in 15 years and my book collection had not been culled), computer manuals and one advisor found what he was looking for in some old computer magazines bought on e-bay.
Some claimed innovations appeared so blindingly obvious that it was difficult to believe that anybody would bother mentioning it in a print. Oracle’s patent 6,910,205
“Interpreting functions utilizing a hybrid of virtual and native machine instructions” (actually a continuation of 6,513,156, filed five years earlier in 1997) describes an obvious method of handling the interface between interpreted and JIT compiled code.
My only implementation experience in this area does predate the Oracle patent (I wrote a native code generator for the UCSD Pascal p-code machine in the mid-80s) but the translation occurred before program execution and so is not appropriate prior art. Virtual machines fell out of favor in the late 80s and when they were revived by Java 10 years later I was no longer working on compilers
Fans of Lisp are always claiming that everything was first done by the Lisp community and there were certainly Lisp compilers around in the 1980s, but I’m not sure if any of them worked during program execution.
Of course Groklaw have started following this case. Kodak has shown that it is possible to win in court over Java related patents. The Sun
Oracle/Microsoft Java lawsuit in the late 1990s was a contract dispute and not about patents/copyright, but still about money/control.
I’m not aware of any previous language implementation patent lawsuits that have gone to court. It will be interesting to see how much success Google have in finding prior art and whether it is possible to implement a JVM that does not make use of any of the techniques specified in the Oracle patents (I suspect that they have a few more that they have not yet cited).