[kaffe] Re: kaffe's license

Jim Pick jim at kaffe.org
Tue Jun 14 10:43:40 PDT 2005

Kiyo Inaba wrote:
> toodulli wrote:
>>I wondering kaffe's license.
>>After I modify kaffe's source code for commercial distribution, I want to
>>use for kaffe virtual machine in digital television settop box.
>>And then, Have I a duty to give money? Where?
> Good to hear someone is trying to deploy the usability of kaffe :-)
> Since kaffe is licensed by GNU General Public License or GPL, you need
> not to pay money at all. The main obligation for you is if you modify some
> part of kaffe, you also have to make this modified portion open.
> See more detail in 
>     http://www.opensource.org/licenses/index.php

I hate to add FUD (fear, uncertainty, doubt) to our own project, but I
think some history of the licensing of the project might be
illustrative.  It's all a bit unclean, unfortunately.

We should right a FAQ on this...

In the early days, Kaffe was released by Tim Wilkinson under a BSD style
license.  When he started a company (Transvirtual) to commercialize the
technology, they started doing newer releases under the GPL, which was
supposed to discourage people from using it in commercial products, so
they could sell their proprietary version.  That business model didn't
actually work very well, and Transvirtual eventually closed down.

The GPL license is somewhat undefined in terms of how it interacts with
other code.  It's not a license I would have chosen for a virtual
machine.  Some people say if you run an application on top of the VM,
you would have to make that application GPL-licensed too.  Some people
say that's nonsense (I tend to agree with that viewpoint).

To my knowledge, I'm not aware of any cases where somebody has been sued
for running non-GPL code on a GPL'd virtual machine.  It's not a common
scenario.  I think Transvirtual actually came to regret re-releasing the
VM under the GPL, since they saw that people were actually using the
GPL'd version for commercial developments, and were not coming to them
for the proprietary version.

The Kaffe project never demanded copyright assignment, so the
intellectual property rights for the various bits in the virtual machine
still reside with the authors of those parts (similar to how the Linux
kernel is owned).  This means that the parts of the virtual machine
contributed by Transvirtual are still owned by whoever has acquired the
assets of Transvirtual.  The company at twincom.net looks like they may
have acquired the assets, but I don't know what sort of legal agreements
they have signed.  Also, other contributors to Kaffe, eg. the people on
this mailing list, own the parts they have contributed.

Personally, I would never sue anybody over using Kaffe for any purpose,
and I'm sure most of the other contributors feel the same way.  I would
like to see users comply with the spirit of the GPL, and contribute
their modifications to the virtual machine back to the project.

However, I cannot 100% guarantee that the whoever holds or buys the
rights to the old Transvirtual stuff might not someday demand compliance
with their interpretation of the GPL, and threaten to sue if that does
not happen.  I suspect that this scenario is somewhat unlikely, since it
would cost a lot of money to sue, the legal case probably isn't very
good, and the amount of damages that they could get would probably be
minimal.  I suspect the current owners of the old Transvirtual IP are
aware that they own it, but they also realize that it would be extremely
difficult to extract any value out of it using this method.

So, if you absolutely can't take any legal risks, you might be better
off just prototyping with Kaffe, and then choosing another
Classpath-based virtual machine to actually put in your product.

If somebody was motivated, we could attempt to track down all the IP
holders that have contributed to Kaffe, and attempt to relicense the
project or get copyright assignment.  That may be difficult though,
especially since some of them have died.  It would probably just be
easier to direct efforts to some of the other virtual machine projects
out there with cleaner licensing, especially since they now share so
much with Kaffe (eg. the Classpath libraries).

That said, I personally don't think that Kaffe's somewhat unclear
licensing situation is much of an obstacle for most uses, so I don't see
any reason not to keep the project going.


 - Jim

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