I came across this post by Matt Finch here, and wanted to offer a small comment on it. The specific quote is reproduced here:
"The tack I've taken with Swords & Wizardry is more along the lines I would have taken with OSRIC if I'd had all the benefits of hindsight. And Swords & Wizardry, unlike the other clones, has an outside agenda of promoting the idea that hobbyist gaming is about taking a basic, open-ended rules framework and then building the custom van at the gaming table itself."
I don't think it is accurate to create this dichotomy of pro-tinkering vs. anti-tinkering. I always assumed by default that all games, and especially old-school games like the retro-clones, promote hobbyist customizing. It's always been in the nature of gamers to do this. I would suggest that there is no way to specifically "promote" this in a game other than to support open gaming by making the material open game content. We shouldn't confuse a product that is more polished as not promoting tinkering. BFRPG, then Labyrinth Lord, and then Swords & Wizardry made their text open game content, in that way supporting open gaming and open development. I think the only clone one might perceive as discouraging tinkering is OSRIC. Part of the reason the whole thing was not made open game content is because some of the contributors to the project are afraid people will change 1e and publish 1e variants.