From the RieselSieve Website

Riesel Sieve is a distributed effort to prove the Riesel conjecture by removing prime candidates for the remaining 101 68 K from over 11 million k/n pairs.

Individual sieving efforts per single K can take months to reach a sufficient level. This coordinated effort will allow us to sieve 100 times deeper and much quicker. No more sieving to 3T and then stopping in frustration as the hours per factor mount, now we can go to 300T and beyond.

LLRNET

Sieving can only eliminate k/n pairs by finding factors. Each factor found eliminates one and sometimes more than one k/n pair. With millions of k/n pairs left in our 2>n<20million range, it will take almost an eternity to completely eliminate all k/n pairs thru sieving alone. Using LLRNET we use special algorithms that can tell whether a k/n pair is prime or composite. LLRNET tests one pair at a time. It takes several hours or more to test each k/n pair using LLRNET, however this is currently our leading way of eliminating k/n pairs. LLRNET WILL find primes. Each prime we find eliminates that k from any further testing as it will be eliminated from being a Riesel Number. Thus, all the n's that go along with said k's will no longer need to be tested.

Sieving eliminates many k's from being LLRNET tested, but at some point the remaining k/n pairs must be tested.

All software needed for our project can be found here.