Awasu allows for sophisticated processing to be performed at all stages of a channel's update cycle.
SOAP is an XML technology that programs can use to communicate with web services.
Channels can have a SOAP request file associated with them that will be sent to the channel's URL using an HTTP POST (instead of the usual HTTP GET). The results will be sent back as a SOAP response which will then typically be converted, using XSLT, into a feed that Awasu can process.
XSLT is an XML technology that can be used to modify an XML document. Awasu deals exclusively with XML data and so is ideally positioned to use this technology.
Channels can have one or more XSLT files associated with them that will be applied to the downloaded feed, modifying it in some way before it is processed by Awasu. For example, items can be removed from the feed, new metadata attached to feed items, the order of the feed items changed, etc.
Used in conjunction with SOAP request files, this is a particularly powerful feature since it allows Awasu to query web services (or any other data source that publishes information using XML) and transform the result into a feed that Awasu can use.