I'm creating a bunch of games similar in style to RPG Maker XP -- 2D, top-down style adventure/action/RPG. I used RPG Maker XP in the past, and their sprites are great. Their content is packaged into something called an "RTP", which is a collection of sprites, tilesets, etc. which is available for exclusive for use with their tool.
Is there an alternative, free RTP I can use out there? Or, is there a large collection of freely-available material I can use? The standard RTP comes with most common tilesets (forest, grassland, desert, snow, 100 types of people, etc.) so I need something similarly comprehensive.
(To summarize, my question is: is there an existing, free to use collection of RPG Maker XP style assets I can use somewhere out on the web?)