[kepler-dev] Re: Kepler

Edward A Lee eal at eecs.berkeley.edu
Sat Nov 8 08:42:01 PST 2003


This looks great... As I told Bertram, we are very enthusiastic about
participating in this.  One contribution we can make in the near term
is to create a skeleton for a "kepler" configuration of Ptolemy II.
A configuration defines the welcome splash page, the documentation files,
and the library of components. It creates a mechanism for "branding" the
effort and customizing what is included and how it is presented.
In development, invoking a configuration is easy:

    vergil -kepler

In deployment, this becomes simply


You can try the "hyvisual" configuration to see what this looks like.

    vergil -hyvisual

Some logistical issues:

1) I've cc'd Christopher Hylands here.  He develops and maintains
    our software infrastructure.  One thing we have to think about is
    how to avoid forking a version of Ptolemy II, which would result
    in future developments not being leveraged across the efforts.
    The separate CVS repository may make this challenging...
    I'm soliciting suggestions from Christopher.

2) I would like to discourage use of the GPL.  We have a policy of
    not including GPL code in Ptolemy II because under its "copyleft"
    manifesto, all the code becomes GPL'd.  This is, effectively,
    a copyright virus.  Part of the reason that we've had impact
    with Ptolemy is that is uses the "BSD" (sometimes called the
    "copycenter") copyright.  Thus, if you guys develop GPL'd
    code, we are unlikely to fold it in to Ptolemy II,
    and hence will end up with forked versions.  The key difference
    is that the BSD copyright permits derivative works without
    imposing the our copyright policy on the derivative work (in fact,
    this why Kepler can use the GPL, if you decide to... if we had a
    GPL-style copyright, you would have no choice).

3) I think that the "development" page on the website should
    "strongly encourage" (whatever that means :-) a common coding style
    that is well documented.  Ours is described at:
    It hasn't been revised in a while, and we are open to suggestions.
    A common coding style makes it much less fatiguing to read each
    other's code.

4) A useful thing to support is Eclipse integration...
    It takes a bit of configuration in the cvs repository to make it
    easy to use Eclipse with the software.


At 03:58 PM 11/7/2003 -0900, Matt Jones wrote:
>Hi Edward,
>Sounds like you had a productive meeting with the SEEK and SDM groups 
>earkier this week.  Thanks for taking the time. We're really excited about 
>the collaboration opportunities with your group, and have been enjoying 
>work with Ptolemy.
>I've been working on a preliminary Kepler page that describes our plans 
>and collaboration (between SEEK and SDM for now, more later).  Its still a 
>work in progress, but you might find it interesting.  We haven't put much 
>up there about the design of the extensions to Ptolemy that we're 
>discussing -- its really just a skeleton site now.
>    http://kepler.ecoinformatics.org
>Let me know if you have any questions.
>Bertram Ludaescher wrote:
>>Thanks for your time today. I'll be in contact re. feedback from the
>>SEEK exec council etc.
>>As for the link to the prelim. Kepler page: Matt Jones will send you
>>this tomorrow.
>Matt Jones                                     jones at nceas.ucsb.edu
>http://www.nceas.ucsb.edu/    Fax: 425-920-2439    Ph: 907-789-0496
>National Center for Ecological Analysis and Synthesis (NCEAS)
>University of California Santa Barbara
>Interested in ecological informatics? http://www.ecoinformatics.org

Edward A. Lee, Professor
518 Cory Hall, UC Berkeley, Berkeley, CA 94720
phone: 510-642-0455, fax: 510-642-2739
eal at eecs.Berkeley.EDU, http://ptolemy.eecs.berkeley.edu/~eal

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