  The integer quantum Hall to insulator transition (IQHIT) is a paradigmatic
quantum critical point. Key aspects of this transition, however, remain
mysterious, due to the simultaneous effects of quenched disorder and strong
interactions. We study this transition using a composite fermion (CF)
representation, which incorporates some of the effects of interactions. As we
describe, the transition also marks a IQHIT of CFs: this suggests that the
transition may exhibit `self-duality'. We show the explicit equivalence of the
electron and CF Lagrangians at the critical point via the corresponding
non-linear sigma models, revealing the self-dual nature of the transition. We
show analytically that the resistivity tensor at the critical point is
$\rho^c_{xx} = \rho^c_{xy} = \frac{h}{e^2}$, which are consistent with the
expectations of self-duality, and in rough agreement with experiments.
