Can this be used to create extension managers as well or is this only possible with C API?

This is very cool! I had not expected that you can add this as an add-on to 8.5.1. I thought we had to wait for 8.5.2 to get OSGi for server tasks.
The setup of the development environment sounds a bit "manual", but anyway, you only do that once.

Would that supersede the TriggerHappy plug-in? Can I have a OSGI plug-in run on an event trigger (e.g. document submitted before routing)?

According to information provided by David in other contexts, the OSGi framework is loaded by the HTTP task, rather than the server core. So this process only works if you're running HTTP services on the server.

@1 & 3 - I have made the same query, but my understanding is that the answer is no. Because the framework is only loaded in the HTTP task, it can't be triggered by other processes which operate independently, such as the Replicator, Router, or AgentMgr.

It would be awesome if the ExtMgr tooling were extended to support Java programs. I bet we would see a surge in server-based procedural tools, then. TriggerHappy would be the tip of the iceberg.

This would be freaking awsome!

By the way, Bob Balfe asked a similar question back in august 2009: { Link }

-Can this be used to create extension managers as well: no this can only be used to create server addin tasks as OSGi plugins. I already have a few ideas on how to build a generic extension manager dll that delegate to an OSGi framework.
-This is very cool! I had not expected that you can add this as an add-on to 8.5.1. I thought we had to wait for 8.5.2 to get OSGi for server tasks: No, there are no dependencies or possible conflicts to 8.5.2 at all. Javaddin is using in own private instance of OSGi framework, in 8.5.2 we use another unrelated instance loaded in the http task.
-From Nathan- So this process only works if you're running HTTP services on the server: Not true, javaddin doesn't use the http services at all. It load a JVM and its own OSGi instance from the {dominobin}\javaddin directory. It doesn't depend or conflict with the 8.5.2 OSGi loaded in the http task. In fact, I wouldn't be surprised if javaddin worked in previous versions of Domino server.
-It would be awesome if the ExtMgr tooling were extended to support Java programs: Yes, it would be very cool, however after making it work, we'll have to mind the performances

>> build a generic extension manager dll
hu, dll ?? isn't this Windooze stuff only

@7: yes you're right, I should have said extension manager library, but I'm sure you understood

@6 - So wait... this is SEPARATE from the OSGi that's loaded by http in 8.5.2? Okay, my bad. But I'm not sure how I feel about that. Can they interact? And if so, can you give us an example of how we'd do that? Preferably one that bears in mind that only about 3 people in the Notes/Domino community have even the most vague understanding of how OSGi actually works.

I'm not sure what use case you have in mind where you feel the http OSGi and Javaddin OSGi need to interact. So I'll try to cover the 2 following scenarios:
1. Runtime interaction: Each instances of OSGi is hosted by a separate process (javaddin.exe and http.exe), therefore they can only interact via Inter-Process communication like Message Queues for example (may be adding a java api to create a new Notes Message queue could be a nice enhancement).
2. Code sharing: plugins and features code could be shared. For example, you could put some plugins and features in a separate directory and create a link file (this is a standard eclipse thing so it's easy to find out how) and then have both instances of OSGi load the plugins in their own processes.

You can't think of any context where you'd like to have Xpages interact with a scheduled process, David? How about scheduled updates to application scopes, like Tag clouds or trending topics?

OK, I got it, the use case is application scopes need to be notified when a scheduled task is done doing some updates. Like I said in my previous post, I think we could achieve that with Message Queues. Definitely something to consider for a future enhancement of Javaddin.

@15: thank you for the kind words. I intend to continue enhancing the tool. I already have quite a few enhancement ideas and if you do too, please send them on.
@16: not at all
@17: Yes, OSGi/Eclipse can be used both as client and server technology. Check out { Link } for more information