XSLT and XSL-FO are related as variants on XSL (eXtensible Stylesheet Language). However, FO refers to Formatting Objects, whereas XSLT refers to Transformations. The difference being that XSLT transforms from one format to another and FO is intended to be used in areas where exact output/positioning is required - such as in printing.
Please submit only sites relating to XSL-FO. General XSL, XSLT content and XSL tools should be submitted into those categories.