Once you have both version on the page they should stay there, partial updates shouldn't affect them. But I don't know enough about how RF 3 handles it to tell you what's happening. That said, RF 3 is rather old, so when you're trying to combine with a new-ish framework you will run into trouble. Can you upgrade to RichFaces 4?
I'm considering to upgrade the application yes. Richfaces 4 require jsf 2 and seam 3. So it means that I should be full migration, also
Richfaces 4 uses jquery 1.6 so it won't help I guess.
It looks like that I simply can't use Richfaces and a4j anywhere (have to remove the jars). Icefaces 3.3.3 uses jquery 1.9.1 but again I'll
need to upgrade to jsf 2 and seam 3.
It doesn't make sense to upgrade to seam 3 as this project is old and no longer supported. Is there any alternative you recommend
to move into ? I am happy to full migration - completely different libraries but it have to java server technologies so I can utilized the existing business
logic (because we put the responsive design as #1 priority).
Here are examples of technologies we are currently using: jpa 1 (entitymanager), envers 1.1, hibernate 3, jboss seam 2.1.2, quartz 2.1, apache poi 3.9, jasper reports (We have jrxml files).