This article is directed towards learning, sharing, validation and dissemination opportunities provided by the online communities for the benefit of software developers. Web- based communities are ideal for learning from other professionals new development methodologies, for receiving code writing tips or acquiring cutting edge algorithms. Online communities are also presented as suitable environments for sharing information, code or even developers when it comes to flexible projects. Web-based communities are rapidly becoming important feedback tools for validating metrics, hypotheses, management methodologies or even pricing policies. Dissemination of results obtained by implementing innovative projects is very cost effective, fast and efficient if online communities are involved. Only innovation focused communities are target by this article and predominantly software development communities are reviewed. The article presents well established communities as well as emerging groups. Software development is chosen as the focus of the article because web-based communities originally consisted solely of programmers. Innovation is the main attribute of successful software development projects and consequently an important segment of any online community. The distinct features of online communities are analysed and ways of exploiting particularities are proposed. Relevant innovation oriented online communities are referred and their specific activities are depicted in the article. Ways to exploit the opportunities created by the online communities are submitted by the author. Learning opportunities are highlighted and information sharing is emphasized as native processes in online communities. The theories, information and facts enunciated throughout the article are summarised. A coherent picture of online communities focused on IT innovation is assembled. In order to access the full paper please contact the author using the Contact form.