Software development requires many different types of knowledge, such as knowledge about software development processes, practices and techniques and about the domain of an application. While developing software, developers share knowledge in informal communication channels (e.g., instant messaging tools, e-mails, or online forums). Considering that this informal communication contains knowledge that may be potentially relevant for other developers and given that this knowledge is not necessarily captured and formally documented for reuse, in this work we will: (a) explore whether developer communication (via instant messaging) is a suitable source of software engineering knowledge; (b) investigate how to identify that knowledge using data mining; (c) and analyse through an action research how to present it to developers in a useful way for reuse. The envisioned knowledge characterization, identification and summarization approaches will analyze existing software development data captured in communication, rather than data that were captured specifically to be ``reused'' for solving a specific task.