As businesses struggle under loads of data, Salesforce.com will jump into the content management market late this year, with software-as-a-service offerings that let users share and tag documents and request alerts when certain types of content are created.

Salesforce Content will include a development platform called Apex Content and content management software called ContentExchange that customers access over the Web for a monthly fee. The products, unveiled last week, stem from the acquisition in March of Koral Technologies.

Salesforce faces established content management rivals including EMC, IBM, and Microsoft. Salesforce's approach is to sell not just the management software as a monthly service, but also hosted storage of the data itself.

Salesforce envisions developers using Apex Content to build Ajax-based user interfaces to access unstructured data stored in Salesforce's data center. The ContentExchange app, meanwhile, will let customers share documents and tag them for easy location (like what users of the Flickr site do with photos). It also lets users subscribe to services, so they get pinged anytime there's a change to a certain document, or there's new content on a topic or by a certain author. That might let an in-house lawyer, for example, get updates on changes to documents governed by Sarbanes-Oxley.