The Web is evolving from a space for publication/consumption of documents to an environment for collaborative work, where digital content can travel and be replicated, adapted, decomposed, fusioned, and transformed. We call this the Fluid Web perspective. This view requires a thorough revision of the typical document-oriented approach that permeates content management on the Web. This paper presents our solution for the Fluid Web, which allows moving from the document-oriented to a content-oriented perspective, where "content” can be any digital object. The solution is based on two axes: a self-descriptive unit to encapsulate any kind of content artifact—the Digital Content Component (DCC) and a Fluid Web infrastructure that provides management and deployment of DCCs through the Web, and whose goal is to support collaboration on the Web. Designed to be reused and adapted, DCCs encapsulate data and software using a single structure, thus allowing homogeneous composition and processing of any digital content, executable or not. These properties are exploited by our Fluid Web infrastructure, which supports DCC multilevel annotation and discovery mechanisms, configuration management, and version control. Our work extensively explores taxonomic ontologies and Semantic Web standards, which serve as a semantic bridge, unifying DCC management vocabularies, and improving DCC description/indexing/discovery. DCCs and infrastructure have been implemented and are illustrated by means of a running example, for a scientific application.