Other representations

. SSA: Single Static Assignment

. RTL: Register transfer language

. Stack machines: P-code

. CFG: Control Flow Graph

. Dominator Trees

. DJ-graph: dominator tree augmented with join edges

. PDG: Program Dependence Graph

. VDG: Value Dependence Graph

. GURRR: Global unified resource requirement representation. Combines PDG with resource requirements

. Java intermediate bytecodes

. The list goes on ......

These are some other types of representations that the compilers use.