Microprossesors/Demo Boards which program in assembly

Hello, I am proficient in assembly language of the Free-scale line of microprocessors and I would like to learn other brands. Can anyone please tell me if there are any other brands of microprocessors, demo-boards, or IDEs that allow programming in assembly? If you know of a specific hyperlink please give me that too. I would like to try physically developing with assembly with another brand. Thank you.