Hey there, handsome!
Brave Halfling Publishing recently released Dagger: Supplemental Rules for Classic Roleplaying with Kids. It comes in two flavors, a free version and one that costs a buck which includes color covers and a better layout. Haven't played it with my kids yet, but hope to do so soon.
Does the cover art look familiar? It should. That's Mark Allen's cover for Brave Halfling's version of the S&W Whitebox, repurposed. I love that artwork. I even found a nice, high resolution version of it over at Lawful Indifferent:
|Click to embiggen to 920 x 1387|
I like this so much I had it as my desktop wallpaper for a long time, centered on a sea of black.
Yeah, this is what you think it is: a fan-edit of the Chainmail rules, cleaned up with a nice cover. Can't reveal the link, sorry. Don't worry, I'm sure dndclassics.com will have this sometime soon.