Similarly to Config selectors, datasources participants can be declared like this:

<participant param="XmlSelectorOs">ParticipantDatasources</participant>

This makes RIFE look up the XML files that declares the datasources dynamically. For example, with this selector it will look for a different name according to the operating system that the application runs under.

For example:

linux     : rep/datasources-linux.xml
MacOSX    : rep/datasources-mac_os_x.xml
Windows XP: rep/datasources-windows_xp.xml

Other available selectors are:

XmlSelectorHostname
XmlSelectorUser

It's of course possible to develop a selector yourself and use it by referring to it with its full class name.