Despite their immense importance to cellular function, the precise mechanism by which chaperonins aid in the folding of other proteins remains unknown. Experimental evidence seems to imply that there is some diversity in how chaperonins interact with their substrates and this has led to a number of different models for chaperonin mechanism. Computational methods have the advantage of accessing temporal and spatial resolutions that are difficult for experimental techniques; therefore, these methods have been applied to this problem for some time. Here we review the relevant computational models for chaperonin function. We propose that these models need not be mutually exclusive and in fact can be thought of as a set of tools the chaperonin may use to aid in the folding of a diverse array of substrate proteins. We conclude with a discussion of the role of water in the chaperonin mechanism, a factor that until recently has been largely neglected by most computational studies of chaperonin function.