[en] Full text: Significant progress has been made on Alcator C-Mod in expanding the configurations and conditions for which the I-mode regime can be accessed and maintained and understanding the physics which underlies the transport improvement. An important result from multi device studies is that the power threshold for I-mode has only a weak dependence on B_t, while the upper power limit increases with B_t, making I-modes more robust at higher field. Experiments in 2015 have extended this trend, achieving clear I-modes at up to 8.0 T. The I-mode regime is naturally stable to ELMs, and combines high τ_E with low particle confinement. This has benefits for fusion reactors, eliminating damaging ELM heat pulses and avoiding impurity accumulation. The τ_E in I-mode is in the H-mode range and has weak power degradation ~P^-0.3. ELITE analysis shows the pedestal to be stable, consistent with this lack of saturation and the absence of ELMs. Nonlinear GYRO simulations show that I-mode core T_i and T_e profiles are stiffer than in L-mode, resembling H-mode with regards to marginal ITG stability. Imode pedestal physics is also advancing, through measurements of fluctuations and flows and using simulations. Both a GAM and a high frequency fluctuation termed theWeakly Coherent Mode are present and strongly interact. Nonlinear BOUT++ simulations agree with many observed features of theWCM. The C-Mod team has been exploring prospects for extrapolation of I-mode to larger fusion devices. We predict ITER would need about 70 MW to enter I-mode. It should be possible to remain in I-mode and to produce high fusion power, provided that density can be sufficiently increased. Accessibility for compact, high-B fusion reactors such as ARC is even more favourable. We are also investigating integration with divertor solutions. Mitigating heat flux using low-Z impurity seeding has been demonstrated, and we have begun to investigate divertor detachment strategies. While robust I-mode operation is typically achieved with ion B x ∇B drift away from the X-point, new experiments show that after the L-I transition, the regime can be maintained in a DN configuration. This may help to reduce peak heat flux. Further I-mode experiments will be a priority in 2016. (author)