The current version (Jan 2012) is v2: API Documentation. It includes feeds for jobs, stories, offices, country vision and supporting data lists in RSS, HTML5, JSON/JSONP, and CSV (file download) formats.
Previous version (Oct 2010) is v1: API Documentation, which is maintained for backwards compatibility for existing feed consumers. It has a jobs feed and supporting data lists in RSS, HTML and JSON/JSONP formats.
We consume these feeds on our public web site www.interserve.org, so we are motivated to keep them working!