MultiSieve was my first foray into writing software related to prime finding.  I was interested in searching for primes of various forms, such as Cullens, Woodalls, and their generalized forms.  No other software could sieve numbers of these forms, so I wrote one.  It originated as a command line program, but grew into a Windows GUI (my first) and added support for many new forms, such as primorials and factorials.

It was with MultiSieve that I found the first megabit Cullen and Woodall primes within weeks of one another, records that stood for years.  I used a MacPPC version of MultiSieve to help me complete all bases to n=10000 on Steven Harvey’s Generalized Woodall search.

MultiSieve creates ABC formatted output, which works great with phrot, LLR, and PFGW.  Follow the link at the left to list all of the known primes found with MultiSieve.

I haven’t done anything with MultiSieve in years because Geoff Reynolds has written a suite of sieving programs that not only run on any CPU, but are faster than MultiSieve.  He had some help from me, but most of the work was his.  His programs include gcwsieve, for Cullens and Woodalls, and fpsieve, used by PrimeGrid for its Primorial and Factorial projects using PRPNet.

There are still some forms that MultiSieve is still the only program out there that can sieve, so it is useful for those.  The most notable form that I am aware of an active search is called a “multi-factorial”, which is hosted by Ken Davis.