The Ultimate Oldgames Linkpage - A large ring with many sites and a resources section.
Warez, Abandonware, and the Software Industry - An article looking at the issues involved in abandonware from both sides.
Free Oldies - Search engine covering many sites. Search by name or sort by genre.
Abandonwarez: The pros outweigh the cons - Article on abandonware from The Adventure Collective.
The Abandonware Ring - The original Abandonware Ring. With a FAQ and a resources section.
Dan's 20th Century Abandonware - Application software from a time not quite forgotten.
Macintosh Garden - Dedicated to preserving abandonware games for the Mac OS.