Contextual collaboration refers to people-to-people collaboration from within IT-enabled business operations. We have designed and implemented a middleware platform for enabling contextual collaboration, and built collaborative applications on top of the platform. The platform embodies three main themes: on-demand, adaptive, and integrated. It is on-demand in that it allows collaboration data and services to be accessed from within business applications as the business need arises. It is adaptive in that it brings the right set of collaboration elements to the user, in a manner sensitive to business context. It integrates collaboration elements across multiple sources, multiple modalities, and multiple vendor technologies. In addition, it integrates structured collaborative activities with ad hoc peer collaboration tools, and with the business processes at large. To validate and leverage the contextual collaboration platform, we have developed an Eclipse-based collaborative development environment and a browser that enables collaborative Web applications. Our contextual collaboration platform and applications promise to yield a more productive and more satisfying business practice.