Subject: Re: Do I owe you money?
Date: Fri, 17 Mar 2000 19:51:43 -0500

Mark Kuharich  wrote:
> I'm curious. I take Linux-Mandrake, JBuilder Foundation Edition, the JDK
> Standard Edition and the JRE for Linux. With Apache/jserv (Tomcat), I
> develop an application that runs on Linux with an HTML UI. It's great.
Now I
> want to distribute it. I'm going to sell a PC with Linux and the JRE and
> servlets. I have no intention of claiming pure anything or using anyone's
> trademarked word in my marketing tools. Every tool I used is supposed to
> free. Do I owe anyone any money for royalties? I'm a little confused by
> issue: If you use open source software, either as is or hack some open
> source code, are you required to open source your resulting software? If
> does this depend on the license (GPL, etc.)?

Possibly.  Unlikely.  The larger risk is that you will have to do a
quid quo pro and give away your software.

You will need to check the license on each item.  Including the Linux
distribution.  Certainly you could put together a package something like
that though which would leave you owing zilch to anyone.

In general if you use a lot of open source applications but build your
application separately, then you are fine.  In your case I would look at
the Mandrake piece carefully.  You certainly should be careful that it is
OK to redistribute any piece of non open source software that they have
aquired permission to package with their distribution.  The easy way out
of that problem is to use a distribution, like Debian, that makes it easy
to figure out which is which so you do will not accidentally ship any
proprietary applications.

If you build an application that links to open source libraries, you will
need to look at the licenses on those libraries very carefully.  If you
see the word "GPL" then you will have to open source your application.
If you see BSD licenses then you can do anything you want.  Others exist
and you may or may not be fine.  For instance Sleepycat gives away
Berkeley DB.  It is open source - if your application is.  If you want to
sell a closed source application that links to it though, then you will
have to negotiate a commercial license with them.

If your application is based on an open source one, or borrows code from
one, that is basically the same set of issues as before but many of the
in-between licenses (eg LGPL) will now flip from allowing closed source
software to not allowing it.  Be very careful about borrowing code!

But there is a simple solution if this is a problem.  What you can do is
build a stand alone open source application on top of the open source
library, and then connect to that.  For instance the application can be
a server with a well-defined API that you communicate to with a socket.
Or you could have the library link to an interpreted free language like
Python or Perl, and then have your application written in that language.
(Take a look at Zope for a sense of what you can do with Python.)