GAG is a Graphical Boot Manager with a lot of features. It doesn't need a partition, it works with primary and extended partitions in every hard disk, it has a lot of icons, it allows you to put passwords for each operating system, it can swap hard disks and it can be tested from diskette. The SafeBoot feature allows you to boot your hard disk even if GAG is overwritten. It includes extensive support for many languages and keyboard types.
ReactOS is an advanced operating system providing a ground-up implementation of a Microsoft Windows XP/Windows Server 2003-compatible operating system. It aims to achieve complete binary compatibility with both applications and device drivers meant for XP and NT 5.2 operating systems by using a similar architecture and providing a complete and equivalent public interface. Written completely from scratch, ReactOS is not a Linux based system, and shares none of the UNIX architecture.