  This paper surveys some of the known results on $\delta$-ideal CR
submanifolds in complex space forms, the nearly K\"{a}hler $6$-sphere and odd
dimensional unit spheres. In addition, the relationship between $\delta$-ideal
CR submanifolds and critical points of the $\lambda$-bienergy is mentioned.
Some topics on variational problem for the $\lambda$-bienergy are also
presented.
