Currently, Koha has three possible frameworks for AJAX: - Biblios, XML-based: Already in use, though only by Biblios. No wrapper, so each of the services has to deal with XML::Simple itself. XML works fairly well, though is slightly more work to deal with than JSON on the browser end. - Tags, JSON-based: This creates JSON objects through interpolation of strings. This works, and avoids the CPAN/JSON dependency, but is error prone, and wouldn't work well for a large number of scripts. - C4::Service (recently sent to patches list, so everything dealing with it is uncertain): I am slightly biased towards this approach because I wrote it, but I think it saves a lot of repetitive work in writing AJAX services. It requires its own script, unlike the approach used for the tags script, which has the disadvantage of requiring some duplicative coding, but this was not too horrible a problem even when writing AJAX circulation. C4::Service was originally part of the AJAX circulation patchset, but this is still in testing, so I decided to send it on its own. It comes with a HTML::Template-ish wrapper around CPAN's JSON module. It might be worth deciding on one or a blend of these approaches, as AJAX will continue to be important. -- Jesse Weaver