Software development is a knowledge-intensive activity and frequently implies a progressive crystallization of knowledge, towards programming language statements. Although wikis have proved very effective, for both collaborative authoring and knowledge management, it would be useful for knowledge acquisition to better support team awareness and the recognition of knowledge structures, their relations, and their incremental evolution. This paper presents Weaki, a wiki prototype especially designed to support incremental formalization of structured contents that uses weakly-typed pages and type evolution. Weaki was applied in academic settings, by students of Software Engineering Labs. Keywords Semantic Wikis, Knowledge Acquisition, Software Engineering