We present a collaborative computing infrastructure that facilitates interactions between distributed applications using the pull-based, event-based model of distributed computing. The collaborative computing infrastructure uses the Atom XML format to provide interoperability between application programs, even if they run on dissimilar computing platforms. The collaborating applications can be programmed in different programming languages and can use different data schema. The Atom server allows applications to publish their output as Atom feed entries for other applications to read using the Atom Publishing Protocol. We have implemented the currently specified Atom Publishing Protocol, which requires feed entries to be retrieved one by one, and also a modified version of the Atom Publishing Protocol, which supports retrieval of all of the feed entries in a collection at once. The modified version results in shorter retrieval times for feed entries, requires fewer connections to the Atom Server for each consumer, and supports larger numbers of concurrent consumers.