Some of the major replacement window manufacturers are Andersen, Pella, Marvin, JELD-WEN, Simonton and Weather Shield. Anderson, Pella and Marvin are the leading window manufacturers as claimed by Consumer Reports. Many of these manufacturers market multiple brands and sell some of their lines to authorized installers only.
These manufacturers produce numerous window styles with wood, vinyl or fiberglass frames. Two of the more popular styles of replacement windows are double-hung windows with a lower inside sash that slides up and an upper outside sash that slides down, and casement-style windows that are hinged on one side and have cranks that allow them to open outward.