Critical Super F-theories
We present F-theories that reduce to 10D Type II Green-Schwarz superstrings. They vary in manifest U-duality according to division between spacetime and "internal" coordinates. They are defined by selfdual current superalgebras in higher worldvolume dimensions with manifest $\mathrm G\times \mathrm G'$ symmetry where the spacetime symmetry $\mathrm G=\mathrm E_{n(n)}$ ranges over the (split form of the) exceptional groups with ranks $n=\mathrm D+1 \leq 7$ and the internal symmetry $\mathrm {G'= GL(10-D)}$.