Using jQuery would include less files and have (hopefully) no chance of conflicts. However, 1 year into the future, when I’m most likely not working here at CERN, what would happen if the system that my application is embedded inside would be updated with a newer jQuery version?

As one doesn’t know the changes in future versions of jQuery (I’ve seen plugins break before), one could run into the risk of having the embedded application stop working, because it wasn’t updated along with jQuery.

This makes a strong point for my development using Dojo instead. Dojo uses it’s own namespace, and if one updates jQuery it shouldn’t affect the Dojo-application. Add to the fact that with Dojo one have less need for 3rd party plugins, as it has got so much more included in the package, and the survivability of the application should be longer.