A computer-implemented method of enabling participation by a first client and a second client in a communication session in a multi-dimensional virtual environment, the multi-dimensional virtual environment having first and second avatars respectively associated with the first and second clients and a plurality of objects distinct from the avatars. The method includes receiving from the first client a first annotation associated with a first object of the plurality of objects, transmitting the first annotation to the second client for display at the second client in association with the first object, receiving from the second client a second annotation associated with a second object of the plurality of objects, and transmitting the second annotation to the first client for display at the first client in association with the second object.