I just received the copy of Labyrinth Lord I bought. Labyrinth Lord is basically a remake of the classic 80's edition of Dungeons & Dragons released under the Open Game License. No mention of the name D&D is made anywhere, for legal reasons, I assume, but the rules should be entirely compatible with old D&D products and all the classic character classes, spells, monsters etc. are there. It covers character levels 1-20 and most of the rules from the Basic and Expert sets, I believe.
The book can also be downloaded from the website, free, in PDF form. So why'd I buy it? Lots of reasons. I was buying a couple other books (from a domestic online service) and needed a little more for free shipping. (I was suprised to find this game in their selection, when our top RPG dealer didn't have it.) It's also a cause I deemed worthy of supporting. And it's also nice to have the classic version of D&D in convenient, compact form.
I do own the D&D Basic Rules set, which I happened to find at a flea market for next to nothing, years and years ago, back when I was first getting into roleplaying games. But the Basic set, of course, only covered character levels 1-3. I later bought the 2nd Edition Advanced Dungeons & Dragons rules (for considerably more money), which we played much more than the Basic version back in the 90's, for the obvious reasons. AD&D is a great game, but there's something really appealing and magical about the simplicity of the classic version.