From its beginning, the Internet has fostered communication, collaboration and networking between users. However, the first boom around the turn of the millennium was mainly driven by a rather one-sided interaction: e-commerce, portal sites and broadcast models of mainstream media were introduced to the Web.

Over the last few years, new tools and practices have emerged which emphasise the social nature of computer-mediated interaction. Commonly (and broadly) labeled as "social software", they encompass applications like weblogs, wikis, social networking sites, instant messaging or collaborative classification systems ("folksonomies"). Growth and diffusion of social software is in part enabled by certain innovative principles of software development (e.g. open-source projects, open APIs, etc.), and in part by empowering the individual user to participate in networks of peers on different scales.

The international conference BlogTalk 2009 will bring together different groups of people using and advancing the Internet and its usage: technical and conceptual developers, researchers with interdisciplinary backgrounds, and practitioners alike. It is designed to initiate a dialog between users, developers, researchers and others who share, analyse and enjoy the benefits of social software. The focus is on social software as an expression of a culture that is based on the exchange of information, ideas and knowledge, and moreover we understand social software as a new way of relating people to people and to machines and vice versa. In the spirit of the free exchange of opinions, links and thoughts, we wish to engage a wide range of participants in this discourse.

BlogTalk 2009 will be two days of meetings, discussions, and exchanges of research, with attendees sharing their experiences, opinions, software developments, and tools.

• We invite developers to discuss the technological developments that are designed to improve the utilisation of social software, as well as reporting about the current state of their software and projects. This will include new weblog and wiki applications, content-creation and sharing environments, advanced groupware and tools, client-server designs, GUIs, APIs, RSS strategies, devices and applications for microblogging and many more.
• Researchers are asked to focus on their visions and interdisciplinary concepts explaining social software including, but not limited to, viewpoints from social sciences, cultural studies, psychology, education, law and natural sciences.
• Practioners will talk about the practical use of social software in professional and private contexts, around topics such as communication improvement, easy to use knowledge management, social software in politics, weblogs and journalism, blogging as a lifestyle, etc.

And finally the most important issue that motivates us: we are looking forward to meeting a lot of people that are fascinated by and work in the online digital world.