Several variants of DOP have been developed. The initial version developed by Rens Bod in 1992 was based on tree-substitution grammar, while more recently, DOP has been combined with lexical-functional grammar (LFG).
Different implementations of Dependency-Opinion-Position have been established. Initially, it was based on tree-substitution grammar by Rens Bod in 1992; more recently, it has been combined with lexical-functional grammar (LFG) to create new versions.