Basics
PLASTIC is a messaging protocol enabling heterogeneous astronomy tools to interoperate and communicate. It has now been superseded by SAMP.
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PLASTIC was inspired by the interoperability work of the Aladin and VisIVO teams. It was realised that extending this interoperability to arbitrary applications would be A Good Thing.
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PLASTIC has been developed under the VOTech project, and the main groups involved include CDS, AstroGrid and INAF, though many others have contributed. Some of the individuals involved are listed here.
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PLASTIC isn't a product, it's a specification. Nevertheless, many "Plasticized" applications are now available to download for your enjoyment. Take a look at PLASTIC apps.
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More information on the design and aims of PLASTIC can be gleaned from the Plastic Manifesto.
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No. PLASTIC is designed to be language and platform neutral. Applications that understand PLASTIC have been written in C++, Python, Perl, Tcl and Ruby and demonstrated to work together.
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Java RMI is just one of the "transport protocols" available to plasticized applications. It has no special status, it is there as a convenience to Java programmers, recognising that many desktop applications are currently being developed in Java. Other transports may be added if there is a need.
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No. PLASTIC has been mainly developed by the VOTech consortium partners, but others have have helped develop the protocol, and contributed plasticized applications. AstroGrid's connection is that they are a member of the consortium and have produced some plasticized software such as the reference Plastic Hub.
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PLASTIC and the Astro Runtime have different purposes. Furthermore PLASTIC is a protocol, while the Astro Runtime is an application that happens also to contain the reference implementation of a Plastic Hub. The differences are summarized quite neatly on this Astro Runtime page.
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Not necessarily. There are Plastic Hubs embedded in Topcat and Aladin.
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There is nothing in the PLASTIC specification that describes how an application could or should be started. The dynamic nature of PLASTIC means that plasticized applications can only communicate with running applications - there is no static registry listing the plasticized applications installed on a user's machine.
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Plasticized applications can be invoked from a web page through a signed Java Applet. There is an example of this on the applications page. Better still, check out Sebastien Derriere's PLASTIC firefox plugin.
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No. Although widely adopted by members of the IVOA, PLASTIC is not endorsed by the IVOA. However, the Applications Messaging Group of the IVOA is currently developing an applications messaging protocol, codenamed SAMP, that has a similar scope and design to PLASTIC. New applications should use SAMP, not PLASTIC.
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The most recent version of the SAMP specification can be found at http://www.ivoa.net/Documents/latest/SAMP.html. At time of writing this is an IVOA Working Draft - we hope that it will become an IVOA Recommendation, without major changes to the existing text, by or near the end of 2008. The apps-samp mailing list (see http://www.ivoa.net/forum/) welcomes contributions and queries from all interested parties.
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After 18 months of practical experience, the PLASTIC developers have a shopping list of changes they'd like to make. Furthermore, the creation of SAMP was an opportunity to address the concernes of IVOA members that are not part of the consortium that developed PLASTIC. Nevertheless, SAMP is very similar to PLASTIC.
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An appendix to the SAMP specification describes the differences.
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SAMP is sufficiently close to PLASTIC that we can produce hubs that speak both protocols and handle the translation. For a transitional period, PLASTIC and SAMP applications will be able to interoperate.
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Although the SAMP specification at time of writing has Working Draft rather than full Recommendation status, the specification text is believed to be sufficiently stable that client authors are recommended to start using it now. Please keep an eye on the apps-samp mailing list to note emerging issues however.
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