Windsor 3 introduces support for Windows performance counters.
Currently Windsor publishes just one counter - "Objects tracked by release policy", which shows you the total number of objects tracked by release policy of given container.
Hunting memory leaks
This is a very useful feature, that will help you quickly validate if you have problems with non-releasing tracked component instances.
Changes
Currently (beta 1) the performance counter is on by default. In future versions, starting with beta 2 it will be off by default.
Using counters
You don't have to do anything to start using this feature. Windsor by default upon startup will inspect if it has all required permissions, and if it does it will ensure the right category and counters are created and will update the counter as the application(s) run.
In order to see the data open Performance Monitor (part of Computer Management console accessible from Administrative Tools section of your Windows Control Panel).
Then click Add (ctrl+N) and find "Castle Windsor" section. As noted above it will contain just one counter - "Objects tracked by release policy", and list of its instances.

For example on the image above you can see there are two instances of the counter. Each of them comes from separate instance of the same application.
After you select them you will be able to track, live, total number of all tracked component instances in each of the containers.