Text-based virtual realities are, in a way, a tribute to solipsism. More specifically, MUDs are a tribute to solipsism (single player text adventures could also work, given the right cirumstances*). First of all, by reading the text and not being given a pre-generated picture, your mind is allowed to form its own image of the reality. Furthermore, in many MUDs, once you reach a certain level (like becoming an avatar at level 50 and being promoted to God), you can actually alter the game universe and create new areas and change old ones.
This is tantamount to Neo realizing he is the one in The Matrix, once he has achieved the necessary amount of experience, he gains the power to alter reality (he becomes a solipsistic god).
*Hex editing, soft ice, source code, etc.