This article presents the findings of a study of French librarians' noninstitutional blogs, which are now acknowledged as a channel of dissemination of professional information. The study has two main objectives: to determine the importance that bloggers give to the concept of ``Library 2.0'' in their posts and to identify the different types of posts and the different discursive genres that they develop to approach this issue. The analysis shows that this question is addressed from various angles: libraries' online presence, interaction with users, development of new services, and training for library staff. The analysis also shows that posts belong to different discursive genres such as opinion papers, accounts of initiatives or experimentations, book reviews, or even descriptions of tools.