Check out Notational Velocity http://notational.net/ http://notational.net/ or its fork nvALT http://brettterpstra.com/projects/nvalt/ http://brettterpstra.com/

Check out Notational Velocity http://notational.net/ http://notational.net/ or its fork nvALT http://brettterpstra.com/projects/nvalt/ http://brettterpstra.com/projects/nvalt/