Our series: Revisiting the Public Domain will be continuing, and will have its own Index Page, once it has a few more entries.
Public Domain Sherpa A very useful tool for tracking down whether something is or is not in the Public Domain, or at least it's a very good start. After this it takes professional researchers, librarians, and lawyers...and money.
---------------------Last Updated: April 29, 2011
Archive(dot)org (The Internet Archive)
A tremendous repository of books, films, audio, and more and all of it in the Public Domain. You could spend entire weeks just mining the amazing lost treasures buried all over the various interconnected sites that make up the Archive.
Everything you need to know, care to know, want to know or just might need to know all in one handy place.
Everything New is Old Again by netherwerks
We go on and on about Public Domain superheroes from the Golden Age, amongst other, related stuff.
A List of FILMS in the Public Domain in the United States
The Free Library
Millions of articles, books and more all of it free and online and ready to go right now.
A quick and painless way to find online references that you probably already know about, but since we dislike assuming things, we included it anyhow.
The University of Nebraska at Lincoln maintains a sizable collection of vintage Government Comics that has to be seen to be believed. Some of this stuff might well prove useful to writers, artists, alternative historians, DMs and other mad-folk.
An online research library that can get you results that Google Books can't and probably won't.
The first place to go to do research on obscure, out-of-print and other characters from across the world.
A wonderful Public Domain Clip-Art site.
Free Audiobooks. Good ones.
Old Book Illustrations
A great place to discover old, vintage, obscure bits of graphics, design elements and full illustrations derived from ... you guessed it ... Old Books.
Open Clip Art Library
A place to browse for clip-art, if you have a need for it--also a good source for reference images.
Your online lending library away from the library.
Photos of the Great War
Photography from World War One. Be warned: you could lose a few hours sifting through this site if the subject matter is at all of any interest to you...and they provide a nice set of links to take you farther down into the trenches...
A great blog devoted to scrounging about and exploring vintage photos and associated things of great interest to anyone interested in said things, like us and maybe two of you lot.
The original and still one of the best sources for Public Domain editions of just about anything/everything that has ever been written/published. It just keeps on growing and getting better--but they need all our support to keep going. Or better yet, you could sign-on as an editor, scanner or other volunteer...and of course they always need charitable contributions...
As explained by Wikipedia
Public Domain Archive (and Reprints)
An experimental site that transitioned into a Search Engine for Public Domain Books.
Public Domain Characters
At Comic Vine. A good place to learn more about who and what's out there in the Public Domain.
Public Domain Clip-Art: Karen's Whimsy
Public Domain Image Resources
Public Domain Resources for Your Game by Netherwerks
Public Domain Superheroes
A site that went from featuring information on Public Domain Superheroes to announcing its transition to becoming a cartoon-blog focused on Public Domain Characters to silence since Jan, 2011. Maybe they're still getting ready?
Public Domain Superheroes (Wikia)
A Wiki focused on Public Domain Superheroes. Yes, it is a theme.
The Public Domain Treasure Hunter
This lady is a hardcore Public Domain researcher and here she offers courses on how to use Public Domain Sources in your work, but we haven't taken any and probably won't as we've been mucking about in this area for a long time now. She does offer some interesting tips and other stuff at her blog/site. Just be aware of the marketing.
Public Domain Wargames (FREE)
A great source for tons of Wargames that have entered the Public Domain, one way or another. You might find our post on this site useful: Public Domain Wargames: Princes, Pole-arms and (tri)Pods.
Rare Book Room
400 of the great classic books of all time digitized and offered up for your education. What wonderful people!
SF Project at Project Gutenberg Australia
A wonderful selection of Speculative, SciFi, and other stuff that you might not find through the normal channels...
Stories and Characters That Have Had Their Copyright Expire
By no means the only list, nor even the most complete, but it is useful, inspirational and worth taking a look at, even if you're not all that sure just what this whole Public Domain thing is about yet.
USGS Map It
A service of the US Geological Survey that allows you to make maps based on real-world data that they have accumulated at tax-payer expense. It'd be fiscally foolish to not use this service.
The Vintage Library
Pulps that you can read from all across the web--a great place to start if you want to find out more about the Pulps and what-all goes along with them...
An online database of images, some of which are in the Public Domain, most are available for use, though a few might cost you some cash...