Several months ago I wrote a draft spec entitled Synchronization of Information Aggregators using Markup (SIAM) which was aimed at providing a lightweight mechanism for aggregators to synchronize state across multiple machines. There was a flurry of discussion about this between myself and a number of other aggregator authors on the [now defunct] information_aggregators mailing list.

However although there was some interest amongst aggregator authors, there wasn't much incentive to implement the functionality for a number of reasons. The reasons range from the fact that it makes it easier for users to migrate aggregators which payware aggregator authors aren't enthusiastic about to the fact that there was no server side infrastructure for supporting such functionality. Ideally this feature would have been supported by a web service end point exposed by a person's weblog or online aggregator. So not much came of it.

Since then I've implemented syncing in RSS Bandit in an application specific manner. So also have the authors of Shrook and NewsGator. There is also the Bloglines Sync API which provides a web service end point to doing limited syncing of feed state whose limitations I pointed out in my post Thoughts on the Bloglines Sync API.

This post is primarily meant to answer questions asked by Dmitry Jemerov, the creator of Syndirella who is now the dev lead for JetBrains' Omea Reader.