OSGi Configuration

Key features:

AEM ConfMgr (since AEM 6.1)

New feature in AEM 6.1, currently not documented officially besides the AEM 6.1 API Docs.

Key features:

Cloud Service Configurations = CSC (since CQ 5.5)

Available in AEM for quite a long time, it's primary usecase is to configure AEM marketing cloud solution integrations or other hosted cloud solutions. But the mechanisms can be used to build custom configuration pages as well, and use the Java API of com.day.cq.wcm.webservicesupport to access this configuration.

Some documentation links:

Key features:

wcm.io Configuration

Open Source Library for AEM, support AEM 6.0, 6.1 and 6.2.

Full documentation: http://wcm.io/config/
adaptTo() Talk: http://adapt.to/2015/en/schedule/building-aem-applications-with-wcm-io.html

Key features: