I don't understand the new paper, but here is the ABC conjecture:<p>Among triples A + B = C, with no common factors between the three, for any given epsilon > 0, there only finitely many with C > R^(1+epsilon); here, R is the "radical" of A,B,C, which is the product of the union of all primes that divide A, B, or C.<p>The difference between R and the product ABC is that we take out any higher powers of the primes. My intuitive interpretation is something like "in almost every irreducible A+B=C, we almost have C < product(primes(A,B,C))."<p>Fermat's last theorem (FLT) is a major consequence. Actually, the only proof I've seen connecting the two shows that FLT can have at most finitely many solutions. Here's a useful survey paper:<p><a href="http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.24.5980" rel="nofollow">http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.24.5...</a><p>(Click on the PDF icon to download the paper for free.)