Also, one could make a distinction between sponsored TLDs and generic TLDs, but that's probably splitting hairs.
I suppose, but they all have similar registry and registrar agreements with ICANN, which is what makes them different from ccTLDs.
at present there are almost as many substantively distinct contracts as there are post-legacy, non-country-code (ASCII and IDN) registries. there are similarities, but there are also distinct differences in registration policy, price caps, and cross ownership. imo, the hair to split is the business models of the operators: there is one business model characterized by $6 FCFS as modified by the UDRP. this business model is common to the VGRS properties, the Afilias and the NeuStar properties. there is another business model characterized by greater restrictions on registrations. this business model is common to the CORE properties and the NCUA property. ppc density in the string space about {google, microsoft, walmart, ibm, vodafone, bank of america, general electric, apple, wells fargo, at&t}* common marks in a namespace is one distinguishing characteristic. another hair to split is the operational practice of ccTLD registries. many lack "nexus" requirements, and share the ppc density of the $6/FCFS/UDRP business model, and quite a few have few registrations other than foreign jurisdiction trademarks. -e * forbes top ten list of 6/15/11.