One of the high-points of OSR for me is Sine Nomine, a one-man company that puts out consistently high-class product. Their web site is about four years out of date, so better sources of info are his
DriveThru catalogue and he uses
Kickstarter for new projects. Kevin’s work is uniformly high quality and his Kickstarter campaigns are gold-standard for delivering and communication.
He has a number of different OSR products with different emphases. Stars Without Number is sci-if, Godbound is a take on the concepts of Exalted. Silent Legions is modern horror. Scarlet Heroes is a fantasy system designed to allow solo-PCs to take on OSR modules by themselves. He recently did Wolves of God which is a more grounded Dark Ages game.
His latest Kickstarter is
Worlds Without Number, a fantasy game to support sandbox play. All his games feature GM tools to help generate gameable material. In that regard, his books are like GURPS books - useful whether you play the game or just as tools to support other games.