CMS that plays well with web services

[jtara]

I'm looking for a CMS or CMS plugin that "plays well" with web services.

I'm working on a proposal to update a web site's architecture. The client wants to maintain content in a CMS. The site is centered on a number of questionnaires that a user fills out, and is provided with content on an ongoing basis based on their answers to the questionnaires.

On the content-creation side, there is probably no need for web services. That is, the CMS's native content-creation facilities will probably be adequate, and content writers will simply use the CMS (with perhaps some help from custom plugins). (For other applications, though, I can certainly see a need - for example, for updating an online sales catalog from a company's internal database.)

On the user side, however, the client would like to maximize flexibility and scalability by implementing a number of web services. For example, some questionnaires are "scored". Others might deliver some text content based on the questionnaire answers. In any case, there might be some considerable "crunching" to produce a result, and it's desired to make this a separate web service.

So, there might be a web service that would calculate the score and/or some text content for a given user's answers to a given questionnaire. The CMS should be able to call the web service in order to plug the score value into a template. Further, the web service should be able to query the CMS itself to retrieve content that it might need in order to do the scoring or content that it will return.

So, the CMS needs to be able to both make use of web services to generate certain content, and also needs to expose it's own content via a web service.

The first case (use an external web service) could certainly be done by writing a custom module for the CMS that "wraps" each web service. The second case might be more difficult with a CMS not specifically designed for this. For example, it might require writing a stand-alone web-services server that accesses the CMS's database using either the CMS's or database's API. But better if there is a CMS that already has built-in support for this.

Anyone have specific recommendations or experience they can share coaxing existing CMSs into a web-services oriented architecture?