1. VO Application interoperability study « VOApp.compareTo(PLASTIC) » Pierre Fernique CDS

2. The goal Cross correlate data by using simultaneously collaborative VO applications Requirements :  Data transfer mechanisms  Cross selection objects/regions  …and a large screen !

3. Example: VOPlot/Aladin cross selections VOPlot reddest objects selections correspond to the Aladin dense regions

4. Some solutions Without cross-selection  usual solution Via files : Save and load => data standards (FITS and VOTable) Via files : Save and load => data standards (FITS and VOTable) Via a Copy and paste function => data standards (OS dependent) Via a Copy and paste function => data standards (OS dependent) With cross-selection  dedicated solution VOApp java interface (new ExtApp version) VOApp java interface (new ExtApp version) PLASTIC hub PLASTIC hub

5. One java machine The technical choices PLASTIC A local daemon (HUB) Events by sockets + predefined messages (via RMI or XML-RPC) VOApp Unique java virtual machine Events by method calls (via a Java interface ) Plastic Hub VOPlot VOApp Topcat API

6. VOApp / Plastic implementations VOAppPLASTIC AladinJavaYesYes APT (STScI HST tool) JavaYesNo AstroGrid tools JavaNo Yes (Astroscope, VAST,…) CADC prototype Java Yes (ExtApp) No TopcatJava Yes VisIVOC++NoYes VOPlotJava No VOSpecJavaNoYes XSA (ESA XMM access tool) java Yes (ExtApp) No Xmdv-toolJavaNoYes

7. VOApp.compareTo(PLASTIC) VOAppPLASTIC Send images/tables YesYes Get images/tables YesNo Cross object selections YesYes Cross image selections Yes – pointing / No - regions Dynamic listeners (ex: mouseMove) Yes (>250 000 events per sec) Yes (<200 events per sec) Sharing memory (for avoiding object/image dupplications) No (Why not ?!) No script messages (ie opened interface) Yes No (Why not ?!) Multi-machine nodes No (in the same JVM) No (Why not ?!) Multi-language No (only java) Yes (via RMI and XMLRPC) Multi-clients Yes (but 1 to 1 oriented) Yes (real broadcast facility) Easy packaging No (both applications should be library compatibles) Yes Easy user usage Yes Yes/No (Hub launching issue ?) Capabilities Implementation

8. Who ? VOApp P.Fernique, F. Ochsenbein [CDS] S. Kale [VO-India] T. Donalson [STScI]  http://aladin.u-strasbg.fr/java /FAQ.html #VOApp PLASTIC J. Taylor, M. Taylor, N. Wistansley [Astrogrid] T.Boch [CDS] M. Comparato [INAF]  http://plastic.sourceforge.net

9. Which one ? PLASTIC  multi-language  generic collaborations  Certainly a good candidate for a new VO standard. VOApp  only in Java world  dedicated collaborations  high performances

10. Comments ?