Below is Joel's note announcing the find of the new prime M1398269. (I shortened the header.) The article he mentioned is here. See my notes on this prime for more links.
From joe@apsydev.com Sat Nov 23 06:04:42 1996
Date: Sat, 23 Nov 1996 10:16:23 +0100
From: Joel Armengaud <joe@apsydev.com>
To: ..
Subject: New Mersenne Prime! [was Re: Mersenne: Factoring bug #2]

Hello Mersenne Searchers,

I am very happy to announce that we have found a new Mersenne Prime!!! This is the 35th known Mersenne number, and the biggest so far:

2**(1398269) - 1
More details can be found at http://www.sjmercury.com

Many thanks to all of you, to you George, who made the fastest program I have ever seen on a Pentium, and to all the Apsylog Development Team fellows, who let me run Prime95.exe on 18 Pentiums and P-PROs.

-Joel Armengaud