1. A method of visualizing versions of a hierarchically organized object, the method comprising the steps of: computing a respective similarity measure between each version and a unique standard version; clustering versions having identical hierarchies into respective sets of versions; organizing versions within each of the respective sets of versions according to the computed respective similarity measures; representing each version as a respective tree having labeled paths; constructing a vector space having multiple dimensions for each labeled path of every tree, wherein the step of constructing the vector space includes constructing each vector in the vector space to have first and second parameters for each respective labeled path, wherein the first parameter indicates a duration for completing work associated with a service and a respective labeled path, wherein the second parameter indicates a cost of providing the work, and wherein the object is a document that indicates a proposal for a service provider to provide the service to a client; generating a visualization having first and second areas that include first and second versions, respectively, wherein the first and second versions each include information from multiple levels of the respective trees; and generating the visualization so that the second version in the second area includes a visual cue that highlights a value of a dimension for a labeled path of the respective tree representing the second version, wherein based on the constructed vector space, the highlighted value differs from a corresponding value of a dimension for a labeled path of the respective tree representing the first version, wherein the step of computing the respective similarity measure includes computing the respective similarity measure between the first and second versions by normalizing a first vector associated with the first version, normalizing a second vector associated with the second version, and determining a product of the normalized first vector and the normalized second vector based on the first parameter indicating the duration and the second parameter indicating the cost, and wherein the steps of computing, clustering, organizing, representing, constructing, generating the visualization having first and second areas, and generating the visualization so that the second version in the second area includes the visual cue are performed by at least one computer.