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 versions of the Dependency-Opinion-Position framework have emerged. Initially, it was founded upon tree-substitution grammar by Rens Bod in 1992; however, more recent developments have integrated it with lexical-functional grammar (LFG).