Well, it was, but it's confusing to people because there's a minefield of trash sites out there. So I'll give everybody the quick rundown on which sites I trust.
- http://www.gog.com is where you should start. If it's there, reputable abandonware sites will just redirect you to the GOG store anyway.
- http://homeoftheunderdogs.net is one of the longest running and best.
- http://www.oldgames.sk DJ Oldgames will have whatever you're hunting, most likely.
- https://archive.org/details/classicpcgames is filling in. Careful that some items are shareware or just demos.
- https://www.myabandonware.com is also reputable, clean layout, and well indexed.
- http://www.reloaded.org Honorable mention. This is NOT abandonware, but an index of community remakes of classic games.
This isn't every reputable site, but the ones I know which also have the most complete listings. Most of them link to other sites as well, so start with these and see where they take you.